The Magentocaloric Effect of Gd5Si2Ge2-XZnX Alloy

The structural and magnetic properties of arc-melted alloys of Gd5Si2Ge2-xZnxin vacuum were investigated by powder x-ray diffraction and Vibrating Sample Magnetometer. When the addition amount of Zn substituted for Ge is less than or equal to 0.05, the alloys have monoclinic Gd5Si2Ge2-type phase structure, the magnetic entropy change of Gd5Si2Ge2-xZnx alloys rapidly increase, When x=0.05, the alloy has the excellent magnetic entropy change (|SM|). When the addition amount of Zn substituted for Ge is more than 0.05, the alloys have the orthorhombic Gd5Si4-type phase structure, the magnetic entropy change of Gd5Si2-xGe2-xZnxalloys rapidly decreases. The Curie temperature (Tc) of Gd5Si2Ge2-xZnx alloys linearly increases and the peak of |SM| is broader with the Zn amount substituted for Ge in Gd5Si2Ge2-xZnxalloys in x range from 0-0.15.

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Magnetic, Magnetocaloric and Magnetoresonance Properties of (1-x)La0.7Sr0.3MnO3/xGeO2 (x=0, 0.15)

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.289.170 ◽

2019 ◽

Vol 289 ◽

pp. 170-176

Author(s):

Tatiana Gavrilova ◽

Ildar Gilmutdinov ◽

Ivan Yatsyk ◽

Tatiana Chupakhina ◽

Julia Deeva ◽

...

Keyword(s):

Magnetic Resonance ◽

Magnetic Entropy Change ◽

Magnetic Ordering ◽

Entropy Change ◽

Magnetic Entropy ◽

Anisotropic Particles ◽

X Ray Diffraction ◽

Absolute Value ◽

X Ray ◽

Magnetic Resonance Spectra

0.85La0.7Sr0.3MnO3/0.15GeO2composite material and pure La0.7Sr0.3MnO3were investigated by X-ray diffraction, scanning electron microscopy, magnetometry and magnetic resonance methods. It was observed that both samples demonstrate the ferromagnetic properties, while the absolute value of the magnetization, the magnetic entropy change and the magnetic ordering temperature decrease in composite in comparison with pure La0.7Sr0.3MnO3. The magnetic resonance spectra of investigated (1-x)La0.7Sr0.3MnO3/xGeO2(x=0, 0.15) can be attributed to the superposition of magnetic resonance spectra from magnetically anisotropic particles with different orientations.

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MAGNETOCALORIC EFFECT IN THE INTERMETALLIC COMPOUND Gd3Ni8Al

Modern Physics Letters B ◽

10.1142/s0217984912501679 ◽

2012 ◽

Vol 26 (25) ◽

pp. 1250167 ◽

Cited By ~ 1

Author(s):

M. X. WANG ◽

H. FU ◽

Q. ZHENG ◽

J. TANG

Keyword(s):

Intermetallic Compound ◽

Magnetocaloric Effect ◽

Single Phase ◽

Magnetic Entropy Change ◽

Magnetic Measurements ◽

Entropy Change ◽

Magnetic Entropy ◽

X Ray Diffraction ◽

X Ray ◽

Refrigerant Capacity

The magnetic properties and magnetocaloric effect of the polycrystalline Gd 3 Ni 8 Al intermetallic compound are studied in this paper. Powder X-ray diffraction shows that the alloy is CeNi 3-type single-phase structure. The magnetic measurements indicate that the compound is ferromagnetic and undergoes a second-order phase transition at 62 K. The maximum of magnetic entropy change reaches 11 J/kg K for the field change from 0 to 50 kOe and the refrigerant capacity of the titled compound is found to be 4.8×102 J/kg.

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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 properties of Gd(Co1-xFex)2 compounds, with x ≤ 0.60

EPJ Web of Conferences ◽

10.1051/epjconf/201818505009 ◽

2018 ◽

Vol 185 ◽

pp. 05009

Author(s):

Maksim Anikin ◽

Evgeniy Tarasov ◽

Nikolay Kudrevatykh ◽

Aleksander Zinin

Keyword(s):

Phase Composition ◽

Diffraction Analysis ◽

Temperature Dependence ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Specific Magnetization ◽

Magnetic Entropy ◽

X Ray Diffraction ◽

X Ray ◽

Magnetocaloric Properties

In this paper the results of specific magnetization and magnetocaloric effect (MCE) measurements for Gd(Co1-xFex)2 system upon the Co substitution by Fe for the x = 0 ÷ 0.60 range are presented. Phase composition was controlled by X-ray diffraction analysis. MCE has been studied within the temperature range of 300-850 K in magnetic fields up to 17 kOe by the magnetic entropy change calculation (ΔSm). It was found that in contrast to the previously studied R(Co-Fe)2 compounds where R = Dy, Ho, Er, an ordinary symmetrical peak of ΔSm(T) in the vicinity of TC is observed for presented samples. Additionally, the MCE comparison of Gd(Co0.88Fe0.12)2 with that for the isostructural Gd(Ni0.88Fe0.12)2 compound having a plateau-like ΔSm temperature dependence is given. The obtained results are discussed.

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Critical Analysis on the Structural and Magnetic Properties of Bulk and Nanocrystalline Cu-Fe-O

Advances in Materials Science and Engineering ◽

10.1155/2010/715872 ◽

2010 ◽

Vol 2010 ◽

pp. 1-14 ◽

Cited By ~ 9

Author(s):

D. Paul Joseph ◽

C. Venkateswaran ◽

R. Selva Vennila

Keyword(s):

High Pressure ◽

Critical Analysis ◽

Profile Analysis ◽

Saed Pattern ◽

Vibrating Sample Magnetometer ◽

Secondary Phases ◽

X Ray Diffraction ◽

X Ray ◽

Paramagnetic Behavior ◽

Structural And Magnetic Properties

Nanocrystalline and bulk samples of “Fe”-doped CuO were prepared by coprecipitation and ceramic methods. Structural and compositional analyses were performed using X-ray diffraction, SEM, and EDAX. Traces of secondary phases such as CuFe2O4, Fe3O4, andα-Fe2O3having peaks very close to that of the host CuO were identified from the Rietveld profile analysis and the SAED pattern of bulk and nanocrystalline Cu0.98Fe0.02O samples. Vibrating Sample Magnetometer (VSM) measurements show hysteresis at 300 K for all the samples. The ferrimagnetic Neel transition temperature () was found to be around 465°C irrespective of the content of “Fe”, which is close to the value of cubic CuFe2O4. High-pressure X-Ray diffraction studies were performed on 2% “Fe”-doped bulk CuO using synchrotron radiation. From the absence of any strong new peaks at high pressure, it is evident that the secondary phases if present could be less than the level of detection. Cu2O, which is diamagnetic by nature, was also doped with 1% of “Fe” and was found to show paramagnetic behavior in contrast to the “Fe” doped CuO. Hence the possibility of intrinsic magnetization of “Fe”-doped CuO apart from the secondary phases is discussed based on the magnetization and charge state of “Fe” and the host into which it is substituted.

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Three-dimensional magnetophotonic crystals based on artificial opals: fabrication and properties

MRS Proceedings ◽

10.1557/proc-834-j2.6 ◽

2004 ◽

Vol 834 ◽

Author(s):

A. V. Baryshev ◽

T. Kodama ◽

K. Nishimura ◽

H. Uchida ◽

M. Inoue

Keyword(s):

Volume Fraction ◽

Three Dimensional ◽

Visible Region ◽

Vibrating Sample Magnetometer ◽

X Ray Diffraction ◽

Dramatic Decrease ◽

X Ray ◽

Magnetophotonic Crystals ◽

Magnetophotonic Crystal ◽

Structural And Magnetic Properties

ABSTRACTWe have fabricated three-dimensional magnetophotonic (3D MPCs) crystals based on artificial opals. Structural and magnetic properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. It was shown that increase of volume fraction of magnetite in the opal lattice leads to a dramatic decrease of transmitted light intensity in the visible region. We also found considerable changes in the Faraday rotation inside the (111) photonic bandgap of an opal—magnetite magnetophotonic crystal.

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Features of Magnetocaloric Effect in Er(Co-Fe)2 Laves Phases

KnE Materials Science ◽

10.18502/kms.v1i1.554 ◽

2016 ◽

Vol 1 (1) ◽

pp. 5 ◽

Cited By ~ 1

Author(s):

M.S. Anikin ◽

E.N. Tarasov ◽

N.V. Kudrevatykh ◽

M.A. Semkin ◽

A.S. Volegov ◽

...

Keyword(s):

Heat Capacity ◽

Phase Composition ◽

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Magnetic Entropy ◽

Concentration Increase ◽

Laves Phases ◽

X Ray ◽

Temperature Range

In this work the results of measurements of heat capacity (CP) and magnetocaloric effect (MCE) in Er(Co1-хFeх)2 system in the concentration range 0.07 ≤ x ≤ 0.80 are presented. Phase composition was controlled by X-ray difraction analysis. Heat capacity was measured in the temperature range 77-320 K. MCE has been studied within the temperature range 5-670 K in magnetic fields up to 70 kOe. It was found that Fe concentration increase caused the table-like (plateau) MCE temperature dependence for both magnetic entropy change date and direct ∆T-effect measurements independently on Fe concentration. The possible reasons of such behavior are discussed.

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Tuning of the Structure and Magnetocaloric Effect of Mn1−xZrxCoGe Alloys (Where x = 0.03, 0.05, 0.07, and 0.1)

Materials ◽

10.3390/ma14113129 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3129

Author(s):

Karolina Kutynia ◽

Piotr Gębara

Keyword(s):

Structural Transformation ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Rietveld Analysis ◽

Significant Rise ◽

Partial Substitution ◽

Magnetic Entropy ◽

X Ray Diffraction ◽

Lattice Constants ◽

Zr Addition

The aim of the present work is to study the influence of a partial substitution of Mn by Zr in MnCoGe alloys. The X-ray diffraction (XRD) studies revealed a coexistence of the orthorhombic TiNiSi-type and hexagonal Ni2In- type phases. The Rietveld analysis showed that the changes in lattice constants and content of recognized phases depended on the Zr addition. The occurrence of structural transformation was detected. This transformation was confirmed by analysis of the temperature dependence of exponent n given in the relation ΔSM = C·(BMAX)n. A decrease of the Curie temperature with an increase of the Zr content in the alloy composition was detected. The magnetic entropy changes were 6.93, 13.42, 3.96, and 2.94 J/(kg K) for Mn0.97Zr0.03CoGe, Mn0.95Zr0.05CoGe, Mn0.93Zr0.07CoGe, and Mn0.9Zr0.1CoGe, respectively. A significant rise in the magnetic entropy change for samples doped by Zr (x = 0.05) was caused by structural transformation.

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Structural, Magnetic, and Magnetocaloric Properties of R2NiMnO6 (R = Eu, Gd, Tb)

10.21203/rs.3.rs-701309/v1 ◽

2021 ◽

Author(s):

K.P. Shinde ◽

E.J. Lee ◽

Maykel Manawan ◽

A. Lee ◽

S.Y. Park ◽

...

Keyword(s):

Magnetic Entropy Change ◽

Ceramic Powder ◽

Double Perovskite ◽

Entropy Change ◽

Cooling Power ◽

X Ray Diffraction ◽

Atomic Size ◽

X Ray ◽

Magnetocaloric Properties ◽

Group A

Abstract Double perovskite Eu2NiMnO6 (ENMO) Gd2NiMnO6 (GNMO) and Tb2NiMnO6 (TNMO) ceramic powder have been synthesized by solid-state reaction and their crystal structure, microstructure, cryogenic magnetic properties, and magnetocaloric performance have been investigated. Structural studies by using X-ray diffraction shows that all compounds crystallize in the monoclinic structure with a P21/n space group. A ferromagnetic to paramagnetic (FM-PM) second-order phase transition occurred in ENMO, GNMO, and TNMO around 143, 130, and 112 K, respectively. The values of maximum magnetic entropy change and relative cooling power at an applied field of 5 T are found to be 3.2, 3.8, 3.5 J/kgK and 150, 182, 176 J/kg respectively, for the studied sample. The change in structural, magnetic, and magnetocaloric effect ascribed to the superexchange mechanism of Ni2+ – O – Mn3+ and Ni2+ – O – Mn4+. Due to different atomic size of Eu, Gd, Tb changes the ratio of Mn4+/Mn3+ which is responsible for the variation of properties significantly in double perovskite.

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Effect of Co substitution on the martensitic transformation and magnetocaloric properties of Ni50Mn35−xCoxSn15

Powder Diffraction ◽

10.1017/s0885715613000225 ◽

2013 ◽

Vol 28 (S1) ◽

pp. S22-S27 ◽

Cited By ~ 1

Author(s):

F.S. Liu ◽

Q.B. Wang ◽

S.P. Li ◽

W.Q. Ao ◽

J.Q. Li

Keyword(s):

Martensitic Transformation ◽

Diffraction Analysis ◽

Powder Diffraction ◽

Magnetic Entropy Change ◽

Magnetic Measurements ◽

Entropy Change ◽

Valence Electron Concentration ◽

Magnetic Entropy ◽

Scanning Calorimetry ◽

X Ray

Martensitic transformation and magnetic entropy change in Co substituted Ni50Mn35−xCoxSn15 (x = 0, 1.0, 1.5, 2.0, and 3.0) Heusler alloys have been investigated by X-ray powder diffraction analysis, differential scanning calorimetry, and magnetic measurements. X-ray diffraction analysis reveals that the Ni50Mn35−xCoxSn15 alloys have L21 Heusler structure at room temperature. The phase decomposition of the sample with x = 3.0, after annealing 48 h at 1173 K, is confirmed by both X-ray powder diffraction analysis and energy-dispersive x-ray spectroscopy in scanning electron microscopy. With the increase of the Co content from 0 to 2.0, the martensitic transformation temperature TM increases from 185 to 245 K, which is in good agreement with the rule of valence electron concentration e/a-dependence of TM. The magnetic entropy change ∆SM is investigated in the vicinity of the martensitic transformation.

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