The Magnetocaloric Properties of (Mn1-XFeX)5Sn3 Compounds Prepared in Magnetic Environment

The crystal structure, microstructure, Curie temperature and magnetocaloric properties of (Mn1-xFex)5Sn3 (x=0.1~0.5) alloys were studied in this paper. The alloys were prepared by powder metallurgy method with magnetic pressing and magnetic sintering. All samples crystallize in the hexagonal InNi2-type structure with space group P63/mmc. The lattice parameter, cell volumes of the (Mn1-xFex)5Sn3 decrease with increasing x, while the Curie temperature of these alloys increases almost linearly with increasing x. All samples exhibit a moderate magnetocaloric effect, and the curves of magnetic entropy change are flat in a wide temperature range, which is suitable for the Ericsson cycle.

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Magnetic properties of the non-stoichiometric TbCo2Nix alloys

EPJ Web of Conferences ◽

10.1051/epjconf/201818504021 ◽

2018 ◽

Vol 185 ◽

pp. 04021

Author(s):

Alexander Inishev ◽

Evgeny Gerasimov ◽

Nikolay Mushnikov ◽

Pavel Terentev ◽

Vasily Gaviko

Keyword(s):

Magnetic Properties ◽

Curie Temperature ◽

Concentration Dependence ◽

Magnetic Moment ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Magnetic Entropy ◽

Thermodynamic Relation ◽

Temperature Dependences

The magnetic and magnetothermal properties of the non-stoichiometric TbCo2Nix (0 ≤ x ≤ 0.2) alloys were studied. It was found that the concentration dependence of the Curie temperature and magnetic moment of the 3d-sublattice have a maximum at x = 0.025. The obtained experimental magnetic properties of the TbCo2Nix alloys were discussed under assumption that the Co magnetic moment in the compounds changes with increasing x. The magnetic entropy change was determined using the temperature dependences of the magnetization and Maxwell’s thermodynamic relation. The obtained results for TbCo2Nix were compared with those for the ErCo2Mnx alloys.

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Study of Magnetic Transition and Magnetocaloric Effect in La1-xSrxMnO3 (0.20≤ x ≤0.35) Compounds

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.378.225 ◽

2013 ◽

Vol 378 ◽

pp. 225-229 ◽

Cited By ~ 1

Author(s):

Yeong Seung Jeong ◽

M.S. Anwar ◽

Faheem Ahmed ◽

Seung Rok Lee ◽

Bon Heun Koo

Keyword(s):

Curie Temperature ◽

Magnetic Entropy Change ◽

Perovskite Phase ◽

Magnetic Transition ◽

Entropy Change ◽

Solid State Reaction Method ◽

Magnetic Entropy ◽

Conventional Solid State Reaction ◽

Ionic Radii ◽

The Difference

We report the magnetic transition and large magnetic entropy change in Sr doped lanthanum manganites. Polycrystalline La1-xSrxMnO3(0.20x0.35) samples were prepared using the conventional solid-state reaction method. The results of X-ray diffraction indicates perovskite phase without any impurity. The magnetic study has revealed that the Curie temperature is influenced by Sr-concentration. The doping of Sr at La site affects the Mn-O bond length and Mn-O-Mn bond angle due to the difference in their ionic radii, consequently, the Curie temperature changed. A large magnetic entropy change has been observed for La0.8Sr0.2MnO3sample, the value of the maximum entropy change (SMmax) increases from 1.42 to 2.74 J/kgK as magnetic field increases from 1 to 2.5 T. This investigation suggests that La1-xSrxMnO3can be used as a potential magnetic refrigeration material.

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Magnetocaloric Properties of Rapidly Solidified Ni51.1Mn31.2In17.7 Heusler Alloy Ribbons

MRS Proceedings ◽

10.1557/proc-1200-g07-05 ◽

2009 ◽

Vol 1200 ◽

Author(s):

Jose Sánchez Llamazares ◽

Blanca Hernando ◽

Víctor Prida ◽

Carlos García ◽

Caroline Ross

Keyword(s):

Melt Spinning ◽

Magnetic Entropy Change ◽

Magnetic Transition ◽

Entropy Change ◽

Single Step ◽

Magnetic Entropy ◽

Refrigerant Capacity ◽

Magnetocaloric Properties ◽

Room Temperature Magnetic Refrigeration ◽

Rapidly Solidified

AbstractMagnetic entropy change and refrigerant capacity have been determined for a field change of 20 kOe around the second-order magnetic transition of austenite in as-quenched Ni51.1Mn31.2In17.7 alloy ribbons produced by melt spinning technique. Samples crystallize in a single-phase austenite with the highly ordered L21-type crystal structure and a Curie temperature of 275 K. The material shows a maximum magnetic entropy change of ΔSMmax= - 1.7 Jkg-1K-1, an useful working temperature range of 78 K (δTFWHM) and a refrigerant capacity of RC=132 Jkg-1 (RC= │ΔSMmax│ x δTFWHM). The considerable RC value obtained together with the fabrication via a single-step process make austenitic Ni-Mn-In ribbons of potential interest as magnetic refrigerants for room temperature magnetic refrigeration.

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Study on Influence of Ca2+ Ions Doping at a Site on Magnetic Properties and Magnetocaloric Effect of Nominal Compositions La1.4Sr1.6-xCaxMn2O7

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1120-1121.406 ◽

2015 ◽

Vol 1120-1121 ◽

pp. 406-413 ◽

Cited By ~ 1

Author(s):

Yun Zong ◽

Di Kang

Keyword(s):

Curie Temperature ◽

Manganese Oxides ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Xrd Analysis ◽

Layered Perovskite ◽

Magnetic Entropy ◽

Doping Amount ◽

Space Group ◽

Room Temperature Magnetic Refrigeration

Polycrystalline layered perovskite manganese oxides La1.4Sr1.6-xCaxMn2O7 (x=0,0.2,0.4,0.8,1.0,1.4,1.6) samples is prepared using solid state reaction.The XRD analysis shows that La1.4Sr1.6-xCaxMn2O7 (0 ≤ x ≤ 0.8) samples are Sr3Ti2O7-type tetragonal structure with space group I4/mmm and forms a layered perovskite structure; for the 1.0≤ x ≤1.6 series of samples the main phase is ABO3 type orthorhombic structure with space group Pbnm.For small amount of Ca2+ ion-doped sample (x= 0.2,0.4), induce serious Jahn-Teller(J-T) distortion of MnO6 octahedral.For a large number of doping (1.0≤ x ≤1.6) samples, ferromagnetic - paramagnetic transition occurs near the Curie temperature (Tc) from low to high temperatures.With increasing doping amount, the magnetization reached maximum at x=1.4 samples.Maximum magnetic entropy change of the three samples(x=1.0,1.4,1.6) reaches 0.84, 1.20 and 2.28 J kg-1 K-1 at 320,268 and 215K near the Curie temperature, respectively. The large magnetic entropy change effect under low magnetic field of the sample makes it an optimal candidate of room temperature magnetic refrigeration materials.

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Field Dependence of the Refrigerant Capacity for La0.6Ca0.4MnO3 Manganite

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.154.163 ◽

2009 ◽

Vol 154 ◽

pp. 163-168 ◽

Cited By ~ 1

Author(s):

R.A. Szymczak ◽

Aleksandra Kolano-Burian ◽

Roman Kolano ◽

R. Puzniak ◽

V.P. Dyakonov ◽

...

Keyword(s):

Magnetic Field ◽

Curie Temperature ◽

Statistical Model ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Relative Cooling Power ◽

Cooling Power ◽

Magnetic Entropy ◽

Refrigerant Capacity ◽

Jahn Teller

The magnetocaloric effect in La0.6Ca0.4MnO3 manganite has been investigated. The isothermal magnetization versus applied magnetic field at various temperatures in the vicinity of Curie temperature was measured, and the temperature dependence of magnetic entropy change was determined using Maxwell’s relation. This value is comparable to that in Gd. Nevertheless, the relative cooling power of La0.6Ca0.4MnO3 was shown to be considerably lower than that of Gd. The experimental results have been analyzed in frames of a phenomenological statistical model. This model considers explicitly Jahn-Teller interactions and allows prediction of the field dependences of the magnetic entropy change and the relative cooling power.

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THE VARIATION OF EXCHANGE CONSTANT AND MAGNETOCALORIC EFFECT IN LaFe13-xSix (x = 1.6, 1.9 AND 2.2) COMPOUNDS

International Journal of Modern Physics B ◽

10.1142/s0217979211101958 ◽

2011 ◽

Vol 25 (25) ◽

pp. 3303-3313 ◽

Cited By ~ 2

Author(s):

T. IZGI ◽

V. S. KOLAT ◽

H. GENCER ◽

S. ATALAY

Keyword(s):

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Wave Dispersion ◽

Lattice Parameter ◽

Exchange Constant ◽

Magnetic Entropy ◽

Arc Melting ◽

Exchange Constants ◽

Si Content

In this work, we present the variation of exchange constant (J exc ) and magnetocaloric effect (MCE) in LaFe 13-x Si x (x = 1.6, 1.9 and 2.2) compounds. NaZn 13-type LaFe 13-x Si x intermetallic compounds were prepared by arc melting in an atmosphere of highly pure argon gas. X-ray results indicated a slight decrease of lattice parameter with increasing Si content. The maximum magnetic entropy change of the LaFe 13-x Si x (x = 1.6, 1.9 and 2.2) samples decreases with increasing Si contents. Also, the magnetic entropy change was calculated theoretically at various magnetic fields and compared with experimental data. The spin-wave dispersion coefficients (D) and exchange constants (J exc ) were calculated for the fist time for these samples. It was found that D and J exc increase with increasing Si content.

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The Magnetocaloric Properties of Gd5Si4 Alloy Prepared by the New Method

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v4i3.6963 ◽

2014 ◽

Vol 4 (3) ◽

pp. 595-600 ◽

Cited By ~ 1

Author(s):

Z. Momeni Larimi

Keyword(s):

Magnetic Entropy Change ◽

Entropy Change ◽

New Method ◽

Second Phase ◽

Arc Furnace ◽

Magnetic Entropy ◽

Orthorhombic Structure ◽

X Ray Diffraction ◽

X Ray ◽

Magnetocaloric Properties

We report on a new method for preparation the magnetocaloric alloy Gd5Si4. By mechanical alloying under argonatmosphere and then melting sample by arc furnace, we produced the Gd5Si4 alloy. The structure and magnetothermalproperties of the alloy have been investigated with the help of powder X-ray diffraction and magnetization measurements.This compound crystallized in the orthorhombic structure with space group pnma. In X-ray powder diffraction pattern, aminor orthorhombic GdSi2 phase was observed as a second phase. For this compound, the second order phase transitionwas observed. The maximum isothermal magnetic entropy change of the Gd5Si4 compound at 348K was found to be -10J/(kg K) in an applied field of 0.5T.

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MAGNETOCALORIC EFFECT IN NANOCRYSTALLINE La0.67Ca0.33Mn0.9V0.1O3

International Journal of Nanoscience ◽

10.1142/s0219581x11007934 ◽

2011 ◽

Vol 10 (01n02) ◽

pp. 291-294 ◽

Cited By ~ 1

Author(s):

P. NISHA ◽

K. G. SURESH ◽

MANOJ RAAMA VARMA

Keyword(s):

Magnetic Entropy Change ◽

Parent Compound ◽

Entropy Change ◽

Lattice Parameter ◽

Magnetic Entropy ◽

Xrd Patterns ◽

Average Size ◽

First Time ◽

Nebulized Spray Pyrolysis ◽

Highly Uniform

Vanadium-substituted La0.67Ca0.33MnO3 is synthesized fully in phase pure and nanocrystalline form for the first time, using nebulized spray pyrolysis. Highly uniform nanoparticles of average size in the range of 31–40 nm as revealed by XRD and TEM studies have been prepared. Rietveld refinement of XRD patterns shows small changes in lattice parameter compared to the parent compound La0.67Ca0.33MnO3 . The transition from ferromagnetic to paramagnetic state takes place over a broad temperature range, which can be attributed to the substitution of V at Mn sites as well as the nanometer size of the particles. Peak magnetic entropy change of these nanopowders was estimated to be about 4.5 J/kgK for a magnetic field of 5 T at 255 K. Compared to the bulk La0.67Ca0.33Mn0.9V0.1O3 , the entropy change of the nanoparticles is found to be smaller.

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