R. Nirmala

Indian Institute of Technology Madras

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S.K. Malik

Universidade Federal do Rio Grande do Norte

A.V. Morozkin

Lomonosov Moscow State University

J. Arout Chelvane

Defence Metallurgical Research Laboratory

K. Sethupathi

Indian Institute of Technology Madras

V. Sankaranarayanan

Indian Institute of Technology Madras

A.V. Morozkin

Lomonosov Moscow State University

S. Quezado

Universidade Federal do Rio Grande do Norte

S. K. Malik

University of Jammu

A. K. Nigam

Tata Institute of Fundamental Research

O. Isnard

Institut Néel

Cooperative Institutions

X-Fab (Germany)

153

Indian Institute of Technology Madras

Lomonosov Moscow State University

Tata Institute of Fundamental Research

Indian Institute of Science Bangalore

Centre National de la Recherche Scientifique

The University of Tokyo

Indian Institute of Technology Bombay

University of Missouri

Indira Gandhi Centre for Atomic Research

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Magnetic properties of ZrNiAl-type R3Mn3GeGa2 compounds (R=Y, Gd, Tb, Dy, Ho and Er)

Journal of Alloys and Compounds (2008)

A.V. Morozkin R. Nirmala J. Arout Chelvane A. K. Nigam

Magnetism

Magnetic structure

Space group

10.1016/j.jallcom.2008.09.145

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Citations (2)

Effect of Hydrogenation on the Magnetic and Magnetocaloric Properties of Rare Earth Intermetallic Compounds Tb0.33Ho0.33Er0.33Ni and Dy0.33Ho0.33Er0.33Ni

Journal of Superconductivity and Novel Magnetism (2024)

Abhaya Prasada Mohapatra A R Dhanya J. Arout Chelvane A.V. Morozkin S. Ramaprabhu

Magnetic refrigeration

10.1007/s10948-024-06747-0

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Large low field magnetocaloric effect in Laves phase intermetallic compounds R'_0.33Ho_0.33Er_0.33Al₂ (R' = Gd, Tb and Dy) and Gd_0.33Dy_0.33Ho_0.33Al₂

P. K. Jesla J. Arout Chelvane R. Nirmala

Polycrystalline Laves phase intermetallic compounds Dy 0.33 Ho 0.33 Er 0.33 Al 2 , Tb 0.33 Ho 0.33 Er 0.33 Al 2 , Gd 0.33 Ho 0.33 Er 0.33 Al 2 and Gd 0.33 Dy 0.33 Ho 0.33 Al 2 have been synthesized and characterized by the means of magnetization measurements. The samples crystalize in MgCu2- type cubic structure (space group Fd-3m) and order ferromagnetically at ~30 K, ~45 K, ~60 K and ~85 K (TC) respectively. Large low field magnetocaloric effect is obtained for these compounds. A combination of these four materials can help build a magnetic refrigerator for hydrogen liquefaction.

10.1109/intermagshortpapers58606.2023.10228308

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New Yb5Sb3-type R5TxX3−x compounds (R=Gd–Er, T=Fe–Cu, X=Sb, Bi)

Journal of Alloys and Compounds (2004)

A.V. Morozkin R. Nirmala S.K. Malik

Powder Diffraction

10.1016/j.jallcom.2004.10.046

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Citations (14)

Tuning the Competing magnetic interactions in RTiGe (R = Tb, Er) Compounds and tailoring the Magnetocaloric effect

arXiv (Cornell University) (2007)

R. Nirmala S. K. Malik

The tetragonal layered compounds TbTiGe and ErTiGe order antiferromagnetically at 276 K and 39 K, respectively. Partial substitution of Mo for Ti in these two compounds modifies the magnetic interactions giving rise to a ferromagnetic ground state which results in an enhanced magnetocaloric effect. The magnetic entropy change in ErTi0.85Mo0.15Ge for a magnetic field change of 5 T is ~10.5 J/kg/K against ~0.8 J/kg/K for ErTiGe in the vicinity of the magnetic transition. Thus, magnetocaloric properties of such layered materials may be tunable by suitable chemical substitutions.

Magnetic refrigeration

Tetragonal crystal system

10.48550/arxiv.0708.3887

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Magnetic structure of Tb2Mn3Si5

Journal of Alloys and Compounds (2002)

R. Nirmala A.V. Morozkin M. Hofmann V. Sankaranarayanan K. Sethupathi

Magnetic structure

Atmospheric temperature range

10.1016/s0925-8388(01)01824-2

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Citations (6)

Magnetocaloric effect in melt-spun Laves phase intermetallic compound HoCo2

Journal of Magnetism and Magnetic Materials (2017)

R. Rajivgandhi J. Rajesh Krishna J. Arout Chelvane S. Quezado S.K. Malik

Magnetic refrigeration

Isothermal process

Melt spinning

Laves phase

10.1016/j.jmmm.2017.08.004

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Citations (8)

Correlation between magnetism and magnetocaloric effect in the intermetallic compound DyNiAl

Journal of Applied Physics (2006)

Niraj Kumar Singh К. Г. Суреш R. Nirmala A. K. Nigam S. K. Malik

Magnetization studies carried out in polycrystalline sample of DyNiAl show the presence of two magnetic transitions, one at 15 K and the other at 30 K. The low-temperature transition is attributed to the onset of antiferromagnetic ordering, while the other one corresponds to the ferro-para transition. Thermomagnetic irreversibility found in the temperature dependence of magnetization data is attributed to the domain-wall pinning effect and also to the magnetic frustration. Magnetocaloric effect is found to be negative in the antiferromagnetic phase and positive above the Néel temperature.

Thermomagnetic convection

Magnetic refrigeration

Magnetism

Néel temperature

10.1063/1.2166589

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Citations (42)

Effect of particle size on electrical and magnetotransport properties of manganite nanoparticles

INTERMAG Asia 2005. Digests of the IEEE International Magnetics Conference, 2005. (2005)

C.R. Krishnamoorthy R. Nirmala K. Sethupati V. Sankaranarayanan S. K. Malik

A systematic study of the particle size effect on electrical, magnetic and colossal magnetoresistance of nanocrystalline Nd/sub 0.7/Sr/sub 0.3/MnO/sub 3/ sample was carried out. Samples were synthesised by citrate auto-ignition method. The resulting precursors were then calcined for 3 h at 700, 800 and 900/spl deg/C to get different particle sizes. To measure electrical resistivity and magnetoresistance, pellets were sintered and quenched to room temperature for 10 minutes at respective calcination temperature. X-ray diffraction patterns, Debye-Scherrer's formula, and transmission electron microscopy were used to approximate crystallite sizes. AC magnetic susceptibility shows a broad transition, due to particle size reduction, with ferromagnetic transition temperature at 130 K. Upon cooling, the electrical resistivity shows an insulator to metal transition at /spl sim/140 K. It is also observed that spin moment values increase with increasing particle size.

Nanocrystalline material

Manganite

10.1109/intmag.2005.1464090

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Multi-magnetic transitions in Tb2Mn3Si5

Journal of Alloys and Compounds (2001)

R. Nirmala V. Sankaranarayanan A.V. Morozkin K. Sethupathi

Ferrimagnetism

Metal–insulator transition

Atmospheric temperature range

10.1016/s0925-8388(00)01451-1

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Citations (7)