Results for "Rachit Nigam"

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Putting in All the Stops: Execution Control for JavaScriptFeb 08 2018Scores of compilers produce JavaScript, enabling programmers to use many languages on the Web, reuse existing code, and even use Web IDEs. Unfortunately, most compilers expose the browser's compromised execution model, so long-running programs freeze ... More
Gesture recognition based mouse eventsJan 09 2014This paper presents the maneuver of mouse pointer and performs various mouse operations such as left click, right click, double click, drag etc using gestures recognition technique. Recognizing gestures is a complex task which involves many aspects such ... More
Performance Analysis of Beacon-Less IEEE 802.15.4 Multi-Hop NetworksJan 14 2012We develop an approximate analytical technique for evaluating the performance of multi-hop networks based on beacon-less CSMA/CA as standardised in IEEE 802.15.4, a popular standard for wireless sensor networks. The network comprises sensor nodes, which ... More
High-order finite elements on pyramids. II: unisolvency and exactnessJun 27 2010Oct 27 2010We present degrees of freedom to accompany the approximation spaces already presented in a companion paper and thus complete the definition of families of high-order conforming finite elements on pyramids for the spaces of the de Rham complex. We prove ... More
A Low Complexity Algorithm and Architecture for Systematic Encoding of Hermitian CodesApr 04 2007Apr 05 2007We present an algorithm for systematic encoding of Hermitian codes. For a Hermitian code defined over GF(q^2), the proposed algorithm achieves a run time complexity of O(q^2) and is suitable for VLSI implementation. The encoder architecture uses as main ... More
High-order finite elements on pyramids: approximation spaces, unisolvency and exactnessOct 05 2006Oct 27 2010We present a family of high-order finite element approximation spaces on a pyramid, and associated unisolvent degrees of freedom. These spaces consist of rational basis functions. We establish conforming, exactness and polynomial approximation properties. ... More
A Brief Review of Helmholtz ConditionsFeb 04 2016Feb 05 2016It is well known that the equations of motion obtained from Newtons second law of motion can be obtained from a Lagrangian via the Euler-Lagrangian formulation if and only if the equations of motion satisfy the Helmholtz conditions. In this pedagogical ... More
Well-posed Bayesian Inverse Problems: Priors with Exponential TailsApr 09 2016May 23 2016We consider the well-posedness of Bayesian inverse problems when the prior measure has exponential tails. In particular, we consider the class of convex probability measures which includes the Gaussian and Besov measures as well as certain classes of ... More
Numerical integration for high order pyramidal finite elementsMar 02 2010We examine the effect of numerical integration on the convergence of high order pyramidal finite element methods. Rational functions are indispensable to the construction of pyramidal interpolants so the conventional treatment of numerical integration, ... More
Enhancing Information Dissemination in Dynamic Wireless Network using Stability and BeamformingOct 19 2012Mobility causes network structures to change. In PSNs where underlying network structure is changing rapidly, we are interested in studying how information dissemination can be enhanced in a sparse disconnected network where nodes lack the global knowledge ... More
Geometric integration on spheres and some interesting applicationsDec 02 2011Geometric integration theory can be employed when numerically solving ODEs or PDEs with constraints. In this paper, we present several one-step algorithms of various orders for ODEs on a collection of spheres. To demonstrate the versatility of these algorithms, ... More
Quantum Dynamics of Complex HamiltoniansJan 30 2016Feb 07 2016Non hermitian Hamiltonians play an important role in the study of dissipative quantum systems. We show that using states with time dependent normalization can simplify the description of such systems especially in the context of the classical limit. We ... More
Universal Packet SchedulingOct 13 2015In this paper we address a seemingly simple question: Is there a universal packet scheduling algorithm? More precisely, we analyze (both theoretically and empirically) whether there is a single packet scheduling algorithm that, at a network-wide level, ... More
Magnetoresistance in granular CrO2 : influence of crystallographic and magnetic microstructureNov 22 2005We report magnetotransport measurements on high purity sintered samples of spintronic CrO2 in an unexplored crystallographic regime between 5-300 K. The negative magnetoresistance (MR) as derived from RH isotherms is observed to be unhysteretic up to ... More
Critical exponents and the correlation length in the charge exchange manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3}Sep 14 2005The critical regime of the charge exchange (CE) manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3} is investigated using linear and non linear magnetic susceptibility and the divergence of the third ordered susceptibility (chi{_3}) signifying the onset of a ... More
Transmitting Video-on-Demand EffectivelyOct 12 2010Now-a-days internet has become a vast source of entertainment & new services are available in quick succession which provides entertainment to the users. One of this service i.e. Video-on-Demand is most hyped service in this context. Transferring the ... More
New Hardness Results for Routing on Disjoint PathsNov 16 2016In the classical Node-Disjoint Paths (NDP) problem, the input consists of an undirected $n$-vertex graph $G$, and a collection $\mathcal{M}=\{(s_1,t_1),\ldots,(s_k,t_k)\}$ of pairs of its vertices, called source-destination, or demand, pairs. The goal ... More
Observation of fluctuation induced tunneling conductance in polycrystalline CrO2Nov 22 2005Intergranular conduction in half metallic CrO2 is known to occur through a combination of spin dependent tunneling (driven by Coulomb Blockade (CB) effects) together with certain spin independent (SI) hopping processes. We present evidence that in polycrystalline ... More
On Computation of Error Locations and Values in Hermitian CodesDec 11 2007We obtain a technique to reduce the computational complexity associated with decoding of Hermitian codes. In particular, we propose a method to compute the error locations and values using an uni-variate error locator and an uni-variate error evaluator ... More
Faster Approximate Distance Queries and Compact Routing in Sparse GraphsJan 12 2012A distance oracle is a compact representation of the shortest distance matrix of a graph. It can be queried to approximate shortest paths between any pair of vertices. Any distance oracle that returns paths of worst-case stretch (2k-1) must require space ... More
A Framework Based Approach for the Development of Web Based ApplicationsFeb 12 2011The sole goal of E-Governance is to allow interaction of government with their citizens in a comfortable & transparent manner. Uniqueness of J2EE makes it a perfect technology for development of any online portal. These involve constancy, easy to replant, ... More
Shortest Paths in MicrosecondsSep 03 2013Computing shortest paths is a fundamental primitive for several social network applications including socially-sensitive ranking, location-aware search, social auctions and social network privacy. Since these applications compute paths in response to ... More
A Fast and Accurate Performance Analysis of Beaconless IEEE 802.15.4 Multi-Hop NetworksAug 06 2014Aug 18 2014We develop an approximate analytical technique for evaluating the performance of multi-hop networks based on beaconless IEEE 802.15.4, a popular standard for wireless sensor networks. The network comprises sensor nodes, which generate measurement packets, ... More
A Proof Theoretic Study of Soft Concurrent Constraint ProgrammingMay 09 2014Concurrent Constraint Programming (CCP) is a simple and powerful model for concurrency where agents interact by telling and asking constraints. Since their inception, CCP-languages have been designed for having a strong connection to logic. In fact, the ... More
Boundary Integral Equations for the Laplace-Beltrami OperatorNov 29 2011We present a boundary integral method, and an accompanying boundary element discretization, for solving boundary-value problems for the Laplace-Beltrami operator on the surface of the unit sphere $\S$ in $\mathbb{R}^3$. We consider a closed curve ${\cal ... More
Rollover Preventive Force Synthesis at Active Suspensions in a Vehicle Performing a Severe Maneuver with Wheels Lifted offSep 08 2013Among the intelligent safety technologies for road vehicles, active suspensions controlled by embedded computing elements for preventing rollover have received a lot of attention. The existing models for synthesizing and allocating forces in such suspensions ... More
Fast integral equation methods for the Laplace-Beltrami equation on the sphereJun 03 2013Integral equation methods for solving the Laplace-Beltrami equation on the unit sphere in the presence of multiple "islands" are presented. The surface of the sphere is first mapped to a multiply-connected region in the complex plane via a stereographic ... More
Mining of product reviews at aspect levelJun 14 2014Todays world is a world of Internet, almost all work can be done with the help of it, from simple mobile phone recharge to biggest business deals can be done with the help of this technology. People spent their most of the times on surfing on the Web ... More
On regularizations of the delta distributionDec 12 2014May 22 2015In this article we consider regularizations of the Dirac delta distribution with applications to prototypical elliptic and hyperbolic partial differential equations (PDEs). We study the convergence of a sequence of distributions $\mathcal{S}_H$ to a singular ... More
Convergence analysis of a multigrid algorithm for the acoustic single layer equationFeb 27 2012We present and analyze a multigrid algorithm for the acoustic single layer equation in two dimensions. The boundary element formulation of the equation is based on piecewise constant test functions and we make use of a weak inner product in the multigrid ... More
Critical behaviour in $La_{0.5}Sr_{0.5}CoO_3$Dec 31 1998We have studied the critical behaviour in $La_{0.5}Sr_{0.5}CoO_{3}$ near the paramagnetic-ferromagnetic transition temperature. We have analysed our dc magnetisation data near the transition temperature with the help of modified Arrott plots, Kouvel-Fisher ... More
Connections for general group actionsSep 14 2003Partial connections are (singular) differential systems generalizing classical connections on principal bundles, yielding analogous decompositions for manifolds with nonfree group actions. Connection forms are interpreted as maps determining projections ... More
Towards the Automated Generation of Focused Proof SystemsNov 13 2015This paper tackles the problem of formulating and proving the completeness of focused-like proof systems in an automated fashion. Focusing is a discipline on proofs which structures them into phases in order to reduce proof search non-determinism. We ... More
Nearly radial Neumann eigenfunctions on symmetric domainsAug 27 2015We study the existence of Neumann eigenfunctions which do not change sign on the boundary of some special domains. We show that eigenfunctions which are strictly positive on the boundary exist on regular polygons with at least 5 sides, while on equilateral ... More
Opinion Mining In Hindi Language: A SurveyApr 19 2014Opinions are very important in the life of human beings. These Opinions helped the humans to carry out the decisions. As the impact of the Web is increasing day by day, Web documents can be seen as a new source of opinion for human beings. Web contains ... More
Slick PacketsJan 08 2012Source-controlled routing has been proposed as a way to improve flexibility of future network architectures, as well as simplifying the data plane. However, if a packet specifies its path, this precludes fast local re-routing within the network. We propose ... More
The cellular dynamics of bone remodeling: a mathematical modelNov 27 2011The mechanical properties of vertebrate bone are largely determined by a process which involves the complex interplay of three different cell types. This process is called {\it bone remodeling}, and occurs asynchronously at multiple sites in the mature ... More
SubGraD- An Approach for Subgraph DetectionMay 22 2012A new approach of graph matching is introduced in this paper, which efficiently solves the problem of graph isomorphism and subgraph isomorphism. In this paper we are introducing a new approach called SubGraD, for query graph detection in source graph. ... More
Abstract Effects and Proof-Relevant Logical RelationsDec 22 2012We introduce a novel variant of logical relations that maps types not merely to partial equivalence relations on values, as is commonly done, but rather to a proof-relevant generalisation thereof, namely setoids. The objects of a setoid establish that ... More
Opinion mining of movie reviews at document levelAug 17 2014The whole world is changed rapidly and using the current technologies Internet becomes an essential need for everyone. Web is used in every field. Most of the people use web for a common purpose like online shopping, chatting etc. During an online shopping ... More
Structural Changes of Active Skeletal Muscles: Modelling, Validation and Numerical ExperimentsApr 01 2015The purpose of this study was to report numerical validation of a 3D finite element model of contracting muscle. The model was based on continuum theory for fibre-reinforced composite materials. Here we simulated contractions for an idealized medial gastrocnemius ... More
The Exponentially Faster Stick-Slip Dynamics of the Peeling of an Adhesive TapeApr 20 2014May 07 2014The stick-slip dynamics is considered from the nonlinear differential-algebraic equation (DAE) point of view and the peeling dynamics is shown to be a switching differential index DAE model. In the stick-slip regime with bifurcations, the differential ... More
Towards the Automated Verification of Cyber-Physical Security Protocols: Bounding the Number of Timed IntrudersMay 27 2016Timed Intruder Models have been proposed for the verification of Cyber-Physical Security Protocols (CPSP) amending the traditional Dolev-Yao intruder to obey the physical restrictions of the environment. Since to learn a message, a Timed Intruder needs ... More
A boundary integral algorithm for the Laplace Dirichlet-Neumann mixed eigenvalue problemNov 01 2014We present a novel integral-equation algorithm for evaluation of Zaremba eigenvalues and eigenfunctions}, that is, eigenvalues and eigenfunctions of the Laplace operator with mixed Dirichlet-Neumann boundary conditions; of course, (slight modifications ... More
Polarity detection movie reviews in hindi languageSep 13 2014Nowadays peoples are actively involved in giving comments and reviews on social networking websites and other websites like shopping websites, news websites etc. large number of people everyday share their opinion on the web, results is a large number ... More
Self-organization of Nodes using Bio-Inspired Techniques for Achieving Small World PropertiesSep 27 2011In an autonomous wireless sensor network, self-organization of the nodes is essential to achieve network wide characteristics. We believe that connectivity in wireless autonomous networks can be increased and overall average path length can be reduced ... More
Self-Organization of Wireless Ad Hoc Networks as Small Worlds Using Long Range Directional BeamsSep 25 2011We study how long range directional beams can be used for self-organization of a wireless network to exhibit small world properties. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. ... More
A Self-Organization Framework for Wireless Ad Hoc Networks as Small WorldsMar 06 2012Motivated by the benefits of small world networks, we propose a self-organization framework for wireless ad hoc networks. We investigate the use of directional beamforming for creating long-range short cuts between nodes. Using simulation results for ... More
Achieving Small World Properties using Bio-Inspired Techniques in Wireless NetworksNov 21 2011Mar 03 2012It is highly desirable and challenging for a wireless ad hoc network to have self-organization properties in order to achieve network wide characteristics. Studies have shown that Small World properties, primarily low average path length and high clustering ... More
Towards Refactoring of DMARF and GIPSY Case Studies -- a Team 8 SOEN6471-S14 Project ReportDec 23 2014Of the factors that determines the quality of a software system is its design and architecture. Having a good and clear design and architecture allows the system to evolve (plan and add new features), be easier to comprehend, easier to develop, easier ... More
Observation of spontaneous magnetization jump and field-induced irreversibility in Nd5Ge3Jul 28 2010We report the observation of spontaneous and ultra-sharp jumps in the low temperature magnetization isotherms of polycrystalline Nd5Ge3. Field-induced and ultra-sharp jumps are also seen in resistivity and heat capacity data. These jumps are accompanied ... More
Magnetization jumps and relaxation effect in doped CeFe2May 21 2010For the first time, we find that the dynamic antiferromagnetic phase present in CeFe2 gets stabilized with Ga and Si substitutions. We find that phenomena such as strain-induced first order jumps in the magnetization curves, asymmetry between the M-H ... More
Observation of re-entrant spin glass behavior in (Ce1-xErx)Fe2 compoundsJul 23 2010Clear experimental evidence of re-entrant spin glass state has been revealed in Er doped CeFe2 compounds. The zero field cooled - field cooled bifurcation in dc magnetization, frequency dependence of freezing temperature, relaxation in zero field cooled ... More
Magneto-transport studies on (Pr1/3Sm2/3)2/3A1/3MnO3 (A = Ca, Sr and Ba) compoundsJun 24 2004Magnetic and transport properties of (Pr1/3Sm2/3)2/3A1/3MnO3 (A = Ca, Sr and Ba) compounds, prepared by the citrate gel route, have been investigated. These compounds are found to crystallize in the orthorhombic structure. Charge ordering transport behavior ... More
Effect of Y substitution on the structural and magnetic properties of Dy1-xYxCo5 compoundsJul 24 2006Structural and magnetization studies were carried out on Dy1-xYxCo5 [x = 0, 0.2, 0.4, 0.6, 0.8, 1] compounds which crystallize in the hexagonal CaCu5-type structure. Lattice parameters and unit-cell volume increase with Y concentration. Large thermomagnetic ... More
Influence of B - site Disorder in $La_{0.5}Ca_{0.5}Mn_{1-x}B_{x}O_{3}$ (B = Fe, Ru, Al and Ga) ManganitesMay 18 2011We have investigated the influence of B - site doping on the crystal and magnetic structure in $La_{0.5}Ca_{0.5}Mn_{1-x}B_{x}O_{3}$ (B= Fe, Ru, Al and Ga) compounds using neutron diffraction, SANS, magnetization and resistivity techniques. The B - site ... More
Anomalous Magnetic Properties in Ni50Mn35In15Oct 10 2008We present here a comprehensive investigation of the magnetic ordering in Ni50Mn35In15 composition. A concomitant first order martensitic transition and the magnetic ordering occurring in this off-stoichiometric Heusler compound at room temperature signifies ... More
Analytical models for Cross-correlation signal in Time-Distance HelioseismologyFeb 19 2007In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface, separated by a fixed angular distance are cross-correlated, and this leads to a wave packet signal. Accurately measuring the travel times of these ... More
Interplay between magnetism and magnetocaloric effect in NdCuSiMay 06 2013We report the magnetic, thermal, magnetocaloric and transport properties of polycrystalline NdCuSi. The compound shows a weak antiferromagnetic ordering, as confirmed by different measurements. Arrott plots indicate that the magnetic phase transition ... More
Magnetism in Gallium doped CeFe_2: The martensitic scenarioMay 23 2008Ce(Fe_{1-x}Ga_x)_2 compounds with x = 0, 0.01, 0.025 and 0.05 have been investigated to unravel the effect of Ga on the magnetic state of CeFe_2. For the first time, we find that the dynamic antiferromagnetic phase present in CeFe_2 gets stabilized with ... More
On the well-posedness of the stochastic Allen-Cahn equation in two dimensionsApr 05 2011Dec 13 2011White noise-driven nonlinear stochastic partial differential equations (SPDEs) of parabolic type are frequently used to model physical and biological systems in space dimensions d = 1,2,3. Whereas existence and uniqueness of weak solutions to these equations ... More
Giant inverse magnetocaloric effect near room temperature in Co substituted NiMnSb Heusler alloysJun 01 2010The effect of Co on the structural, magnetic and magnetocaloric effect (MCE) of Ni50-xCoxMn38Sb12 (x=0,2,3,4,5) Heusler alloys was studied. Using x-ray diffraction, we show the evolution of the martensitic phase from the austenite phase. The martensitic ... More
Irreversibility of field-induced magnetostructural transition in NiCoMnSb shape memory alloy revealed by magnetization, transport and heat capacity studiesJun 01 2010The effects of magnetic field on the martensitic transition have been studied in Ni45Co5Mn38Sb12. We find a large field-induced irreversibility in this system, as revealed by the field dependence of resistivity, magnetization, and heat capacity data. ... More
Supression of electron correlations in the superconducting alloys of Rh$_{17-x}$Ir$_x$S$_{15}$Oct 23 2009Oct 15 2010We have studied the effect of Iridium doping (Rh$_{17-x}$Ir$_{x}$S$_{15}$) in the Rhodium sites of the strongly correlated superconductor Rh$_{17}$S$_{15}$. Even at low levels of doping (x = 1 and 2) we see a drastic change in the superconducting properties ... More
Co-existence of ferromagnetic and antiferromagnetic interactions in Mn$_3$Ga$ _{(1-x)} $Sn$_x$CApr 07 2014The magnetic properties of the Mn$_3$Ga$_{(1-x)}$Sn$_x$C, 0 $\le$ x $\le$ 1 antiperovskite compounds have been investigated in detail. Though all compounds of this series crystallize in a cubic structure, the Ga rich (x $\le$ 0.2) compounds transform, ... More
Provenance-Centered Dataset of Drug-Drug InteractionsJul 20 2015Over the years several studies have demonstrated the ability to identify potential drug-drug interactions via data mining from the literature (MEDLINE), electronic health records, public databases (Drugbank), etc. While each one of these approaches is ... More
Observation of large positive magnetoresistance and its sign reversal in GdRhGeFeb 18 2013Nov 13 2013Magnetic properties, heat capacity and magnetoresistance (MR) of polycrystalline GdRhGe are investigated. It shows two antiferromagnetic transitions, one at T1=31.8 K and the other at T2=24 K, and field induced metamagnetic transition over a wide temperature ... More
Magnetic, magnetocaloric and magnetotransport properties of RSn_{1+x}Ge_{1-x} compounds (R=Gd, Tb, Er; x=0.1)Jul 20 2012We have studied the magnetic, magnetocaloric and magnetotransport properties of RSn1+xGe1-x(R=Gd, Tb, Er; x=0.1) series by means of magnetization, heat capacity and resistivity measurements. It has been found that all the compounds crystallize in the ... More
A phenomenological model for magnetoresistance in granular polycrystalline colossal magnetoresistive materials: the role of spin polarised tunnelling at the grain boundariesMay 20 1998It has been observed that in bulk and polycrystalline thin films of collossal magnetoresistive (CMR) materials the magnetoresistance follows a different behaviour compared to single crystals or single crystalline films below the ferromagnetic transition ... More
Magnetic and the magnetocaloric properties of Ce1-xRxFe2 and Ce(Fe1-xMx)2 compoundsMay 31 2010We have studied selected rare earth doped and transition metal doped CeFe2 compounds by examining their structural, magnetic and magneto-thermal properties. With substitution of Ce by 5 and 10% Gd and 10% Ho, the Curie temperature can be tuned to the ... More
Magnetic and electrical properties of RCo2Mn (R=Ho, Er) compoundsOct 11 2009The RCo2Mn (R= Ho and Er) alloys, crystallizing in the cubic MgCu2-type structure, are isostructural to RCo2 compounds. The excess Mn occupies both the R and the Co atomic positions. Magnetic, electrical and heat capacity measurements have been done in ... More
Sm2Al: Another ferromagnet with spin-orbital compensation?Apr 22 2007We report the observation of a compensation point in the temperature dependence of magnetization data of polycrystalline Sm2Al. Magnetization measurements show that this compound magnetically orders at about 150 K. Below this temperature, the magnetization ... More
Signature effects of spin clustering and distribution of spin couplings on magnetization behaviour in Ni-Fe-Mo and Ni-Fe-W alloysJan 01 2011Jan 13 2011The spontaneous magnetization as a function of temperature is investigated for a number of disordered Ni-Fe-Mo and Ni-Fe-W alloys using superconducting quantum interference device magnetometry, with a focus on the low-T behavior as well as the critical ... More
Anomalous magnetoresistance and magnetocaloric properties of NdRu2Ge2Oct 05 2012It is found that the polycrystalline NdRu2Ge2 undergoes two successive magnetic transitions at Tt=10 K and TN=19 K. Evidence of metamagnetic transition is detected in the magnetization isotherm data in the antiferromagnetic regime. Temperature dependence ... More
Anomalous magnetic, transport and thermal properties of Gd5Ge3Nov 12 2012We have studied the magnetic, thermal and magnetotransport properties of polycrystalline Gd5Ge3. It is found that the compound is a strong antiferromagnet and does not undergo any strong metamagnetic transition even in a field of 90 kOe. However, a small ... More
Observation of enhanced exchange bias behavior in NiCoMnSb Heusler alloysJun 01 2010We report the observation of large exchange bias in Ni50-xCoxMn38Sb12 Heusler alloys with x=0, 2, 3, 4, 5, which is attributed to the coexistence of ferromagnetic and antiferromagnetic phases in the martensitic phase. The phase coexistence is possibly ... More
Magnetic, magnetocaloric and transport properties of HoRuSi compoundJan 16 2013Magnetic, thermal, magnetocaloric and transport properties of polycrystalline HoRuSi have been studied. It was found that the compound shows magnetic transitions at T1=18 K and T2=8 K. Magnetization data reveal that the ferromagnetic ordering is dominant ... More
Change in the order of magnetic transition in HoRhGe as probed by magnetoresistance and magnetocaloric studiesJan 25 2013Magnetoresistance and magnetocaloric properties of polycrystalline HoRhGe have been studied. This compound orders antiferromagnetically with a Neel temperature (TN) of 5.5 K and undergoes a first order metamagnetic transition at 2 K. It shows a large ... More
How large can the first eigenvalue be on a surface of genus two?Sep 18 2005Sharp upper bounds for the first eigenvalue of the Laplacian on a surface of a fixed area are known only in genera zero and one. We investigate the genus two case and conjecture that the first eigenvalue is maximized on a singular surface which is realized ... More
Anomalous magnetization behavior in Ce(Fe,Si)2Oct 28 2008We report the effect of Si doping on the magnetization behavior of CeFe2. It is found that Si stabilizes the dynamic antiferromagnetic state of CeFe2. Multi-step magnetization behavior, unusual relaxation effect, thermal and magnetic history dependence, ... More
Room Temperature Magnetocaloric Effect in Ni-Mn-InNov 19 2007We have studied the effect of magnetic field on a non-stoichiometric Heusler alloy Ni$_{50}$Mn$_{35}$In$_{15}$ that undergoes a martensitic as well as a magnetic transition near room temperature. Temperature dependent magnetization measurements demonstrate ... More
Effect of carbon content on magnetostructural properties of Mn$_3$GaCApr 07 2014Effect of carbon content on magnetostructural transformation in antiperovskites of the type Mn$_3$GaC$_x$ ($x$ = 0.8, 1.0 and 1.05) has been investigated. It is found that, increase in carbon content changes the ground state from ferromagnetic metallic ... More
Relaxation of thermo-remanent magnetization in Fe-Cr GMR multilayersMay 06 2005The time decay of the thermo-remanent magnetization (TRM) in Fe-Cr giant magnetoresistive (GMR) multilayers has been investigated. The magnetization in these multilayers relaxes as a function of time after being cooled in a small magnetic field of 100 ... More
Thermodynamic Properties of Ferromagnetic Mott- Insulators GaV4S8Jun 02 2007We present the results of the magnetic and specific heat measurements on V4 tetrahedral-cluster compound GaV4S8 between 2 to 300K. We find two transitions related to a structural change at 42K followed by ferromagnetic order at 12K on cooling. Remarkably ... More
Stabilization of antiferromagnetism in CeFe2 alloys: Effects of chemical and hydrostatic pressureMay 20 2010Effects of Al, Mn and Sb dopings in CeFe2 and effect of applied pressure have been investigated. Al doping gives rise to the FM-AFM transition and a reduction in the magnetic moment and TC values, clearly indicating the growth of the AFM component. Mn ... More
Magnetic, magneto-thermal and magneto-transport properties in SmMn2Si2-xGex compoundsMay 15 2007The effect of Ge substitution for Si in SmMMn2Si2-xGex compounds has been studied. The Sm ordering temperature is found to be much larger in the compound with x=2, as compared to the compounds with x=0 and 1. The increase in the intra layer Mn-Mn distance ... More
Effect of Ge substitution for Si on the anomalous magnetocaloric and magnetoresistance properties of GdMn2Si2 compoundsSep 15 2006The effect of Ge substitution on the magnetization, heat capacity, magnetocaloric effect and magnetoresistance of GdMn2Si2-xGex (x=0, 1, and 2) compounds has been studied. The magnetic transition associated with the Gd ordering is found to change from ... More
Role of heterostructures and multiple magnetic phases in the low-field magnetization of Fe-Cr GMR multilayersApr 12 2005Zero-field-cooled (ZFC) and field-cooled (FC) magnetization along with ac-magnetization vs. temperature and m-h loop measurements are reported for two series of ion-beam sputtered Fe-Cr GMR multilayers where the interface roughness is different. The exchange ... More
Magnetic and transport properties of Mo substituted La0.67Ba0.33Mn1-xMoxO3 perovskite systemAug 05 2005The effect of doping Mo for Mn on the magnetic and transport properties of the colossal magnetoresistance material, La0.67Ba0.33MnO3, has been studied. Compounds of the series La0.67Ba0.33Mn1-xMoxO3 (x=0.0 to 0.1) have been prepared and found to crystallize ... More
Field dependent competing magnetic ordering in multiferroic Ni3V2O8Jun 25 2009The geometrically frustrated magnet Ni3V2O8 undergoes a series of competing magnetic ordering at low temperatures. Most importantly, one of the incommensurate phases has been reported to develop a ferroelectric correlation caused by spin frustration. ... More
Sharp magnetization step across the ferromagnetic to antiferromagnetic transition in doped-CeFe$_2$ alloysMay 25 2005Very sharp magnetization step is observed across the field induced antiferromagnetic to ferromagnetic transition in various doped-CeFe$_2$ alloys, when the measurement is performed below 5K. In the higher temperature regime (T$>$5K) this transition is ... More
The effect of the total density of states at Fermi level on spin polarised tunnelling in granular La0.55Ho0.15Sr0.3MnO3Nov 27 1998We study the spin polarised tunnelling mechanism through magnetisation and magnetoresistance in the granular polycrystalline colossal magnetoresistive manganite, La0.55Ho0.15Sr0.3MnO3. This system has a ferromagnetic transition temperature (Tc) of 255 ... More
Raman and Infrared spectra of (BaF2)n (n=1-6) clustersMay 01 2015The vibrational properties of alkaline-earth metal fluoride clusters (BaF2)n (n=1-6) are investigated in the framework of density functional theory. The calculated Raman and Infrared (IR) spectra reveals shift in Raman and IR peak position towards lower ... More
Thermal and Transport Behavior of Single Crystalline R2CoGa8 (R = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) CompoundsMar 09 2009The anisotropy in electrical transport and thermal behavior of single crystalline R$_{2}$CoGa$_{8}$ series of compounds is presented. These compounds crystallize in a tetragonal structure with space gropup P4/mmm. The nonmagnetic counterparts of the series ... More
Field induced changes across magnetic compensation in Pr(1-x)Gd(x)Al(2) alloysAug 23 2010The magnetic compensation phenomenon has been explored in the Pr(1-x)Gd(x)Al(2) series. The contributions from Pr and Gd moments compensate each other at a specific temperature in the ordered state (below (T(c)). At high fields, the magnetic reorientation ... More
Metastable magnetization behavior in magnetocaloric R6Co1.67Si3 (R=Tb and Nd) compoundsMay 20 2010Magnetic field and time induced steps have been observed in the recently discovered ternary silicide R6Co1.67Si3. Huge relaxation steps are observed across different loops in the low temperature magnetization isotherms. Giant relaxation present in this ... More
Role of coexisting ferromagnetic and antiferromagnetic phases on the magnetocaloric effect in metamagnetic Tb2Ni2SnSep 14 2006Oct 06 2006We report the anomalous magnetocaloric behavior in the polycrystalline compound Tb2Ni2Sn. The magnetization measurements show that this compound shows multiple magnetic transitions, which are attributed to the coexistence of ferromagnetic and antiferromagnetic ... More
Role of Fe substitution on the anomalous magnetocaloric and magnetoresistance behavior in Tb(Ni1-xFex)2 compoundsSep 16 2006We report the magnetic, magnetocaloric and magnetoresistance results obtained in Tb(Ni1-xFex)2 compounds with x=0, 0.025 and 0.05. Fe substitution leads to an increase in the ordering temperature from 36 K for x=0 to 124 K for x=0.05. Contrary to a single ... More
RRhGe (R=Tb, Dy, Er, Tm): An experimental and theoretical studyNov 17 2014RRhGe (R=Tb, Dy, Er, Tm) compounds have been studied by a number of experimental probes and theoretical ab initio calculations. These compounds show very interesting magnetic and electrical properties. All the compounds are antiferromagnetic with some ... More
Low temperature synthesis, magnetic and magnetotransport properties of (La1-xLux)0.67Ca0.33MnO3 (0 < x < 0.12) systemAug 06 2004We have been able to synthesize Lu+3 substituted La0.67Ca0.33MnO3 (LCMO) by an auto-combustion method. Synthesis of this compound is not successful by conventional ceramic or other chemical methods. Magnetic and electrical transport properties of the ... More