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

2013 ◽  
Vol 28 (S1) ◽  
pp. S22-S27 ◽  
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.

MAGNETOCALORIC EFFECT IN THE INTERMETALLIC COMPOUND Gd3Ni8Al

2012 ◽  
Vol 26 (25) ◽  
pp. 1250167 ◽  
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.

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

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.

The Magentocaloric Effect of Gd5Si2Ge2-XZnX Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 525-529
Author(s):  
Xue Ling Hou ◽  
Jie Xiang ◽  
Zhi Zeng ◽  
Jian Huang ◽  
Xue Zhen Wang ◽  
...  
Keyword(s):  
Phase Structure ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Vibrating Sample Magnetometer ◽  
Magnetic Entropy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Type Phase ◽  
Structural And Magnetic Properties ◽  
Addition Amount

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.

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

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.

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

2016 ◽  
Vol 1 (1) ◽  
pp. 5 ◽  
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

<p>In this work the results of measurements of heat capacity (C<sub>P</sub>) and magnetocaloric effect (MCE) in Er(Co<sub>1-</sub><sub>х</sub>Fe<sub>х</sub>)<sub>2</sub> 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.</p>

The Magnetocaloric Properties of Gd5Si4 Alloy Prepared by the New Method

2014 ◽  
Vol 4 (3) ◽  
pp. 595-600 ◽  
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.

Large Room Temperature Magnetocaloric Effect in Ni50Mn34(Co,Cu)In15

2013 ◽  
Vol 316-317 ◽  
pp. 996-1001 ◽  
Author(s):  
Zhe Li ◽  
Chao Jing ◽  
Jun Jun Wu ◽  
Ling Xian Wu ◽  
Jian Yin ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Exchange Interaction ◽  
Magnetocaloric Effect ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Parent Phase ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Room Temperature Magnetic Refrigeration ◽  
Ferromagnetic Ordering

Effect of Co or Cu slightly introduced in Ni50Mn35In15on martensitic transformation and magnetocaloric effect was investigated. The small doping of Co can modify exchange interaction between Mn atoms, resulting in the ferromagnetic ordering of the parent phase and a large magnetization difference across the martensitic transformation. For Cu-doped sample, a large was obtained, and gives rise to a large magnetic entropy change of 58.4 J/kg K for 5 T near room temperature accompanying with smaller hysteresis losses. The study on the doping system may have significant impact on realization of room-temperature magnetic refrigeration.

Magnetocaloric Effect of Ni44Co6Mn40CuxSn10-x Quinary Alloy Comes from the Martensitic Transformation

2018 ◽  
Vol 787 ◽  
pp. 17-24
Author(s):  
Zhen Gang Guo ◽  
Hong Mei Qiu
Keyword(s):  
Martensitic Transformation ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Valence Electron Concentration ◽  
Martensitic Transition ◽  
Critical Temperatures ◽  
Austenitic Phase ◽  
Cu Content ◽  
Cu Substitution

The structure, martensitic transition and magnetic properties of Ni44Co6Mn40CuxSn10-x quinary alloy are investigated systematically. The substitution of Cu for Sn is found to reduce the symmetry of crystal structure, showing an evolution from cubic to tetragonal phase at room temperature. Two magnetic transitions were observed in the alloys, martensitic transition and Curie transition. The critical temperatures of martensitic transformation are found to increase nearly linearly with increasing valence electron concentration caused by Cu substitution for Sn, while Curie temperature of the austenitic phase decreases with the increasing Cu content in the alloys. The Ni44Co6Mn40CuxSn10-x alloys have a large magnetic entropy change across the martensitic transition, reaching 26.8 Jkg-1K-1 under a field change of 3T, because of the strong coupling between structure and magnetism, which shows a great applicable prosperity in magnetic refrigeration technology.

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