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

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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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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Magnetocaloric Effect in RFe10X2( X=Mo, V)

International Journal of Computational Physics Series ◽

10.29167/a1i1p102-113 ◽

2018 ◽

Vol 1 (1) ◽

pp. 102-113

Author(s):

Raghda Abu El-Nasr ◽

Samy H. Aly ◽

Sherif Yehia ◽

Hala A. Sobh

Keyword(s):

Heat Capacity ◽

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Mean Field ◽

Entropy Change ◽

Field Analysis ◽

Electronic Contribution ◽

Sublattice Model ◽

Magnetic Entropy ◽

Field Change

We present a mean-field study on the magnetocaloric effect (MCE) in RFe10X2, where X=Mo, V, and R=Gd, Tb, Ho, Tm, Dy, Er, Nd for X=V. For X=Mo, R=Dy, Gd, and Nd. The two-sublattice model, involving the 4f (rare earth) and 3d(Fe) sublattices, is used. For both systems, magnetization, magnetic heat capacity, magnetic entropy and isothermal entropy change ∆Sm are calculated for different magnetic fields in the 0-5T range and the temperature range from 0 to 700K. Direct and inverse MCEs are shown to take place in these ferromagnetic/ferrimagnetic compounds. For a field change ∆H=5T, the maximum isothermal magnetic entropy change has been calculated for ferromagnetic NdFe10Mo2 compound to be 6.6 J/K mol at Tc=441 K. Both direct, and inverse MCEs have been found in ferrimagnetic compounds, e.g., for TmFe10V2, with maximum -∆Sm= J/K mol at Tc=521K and ∆Sm= J/K mol at TN=127 K. Mean-field analysis is suitable for handling the systems we report on. Further study on the lattice and electronic contribution to entropy is planned.

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Giant low-field reversible magnetocaloric effect in HoCoGe compound

RSC Advances ◽

10.1039/c6ra24527g ◽

2016 ◽

Vol 6 (108) ◽

pp. 106171-106176 ◽

Cited By ~ 5

Author(s):

Y. Zhang ◽

Q. Y. Dong ◽

L. C. Wang ◽

M. Zhang ◽

H. T. Yan ◽

...

Keyword(s):

Low Temperature ◽

Magnetocaloric Effect ◽

Temperature Change ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Magnetic Entropy ◽

Temperature Range ◽

Low Field ◽

Adiabatic Temperature Change ◽

Attractive Candidate

HoCoGe compound shows large magnetic entropy change and adiabatic temperature change, which makes it an attractive candidate for magnetic refrigeration in the low temperature range.

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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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Large magnetic entropy change at cryogenic temperature in rare earth HoN nanoparticles

RSC Advances ◽

10.1039/c6ra16356d ◽

2016 ◽

Vol 6 (79) ◽

pp. 75562-75569 ◽

Cited By ~ 4

Author(s):

K. P. Shinde ◽

S. H. Jang ◽

M. Ranot ◽

B. B. Sinha ◽

J. W. Kim ◽

...

Keyword(s):

Rare Earth ◽

Low Temperature ◽

Magnetocaloric Effect ◽

Cryogenic Temperature ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Environmental Problems ◽

Magnetic Refrigeration ◽

Magnetic Entropy ◽

Alternative Technology

The most extensive cooling techniques based on gases have faced environmental problems. The magnetic refrigeration is an alternative technology based on magnetocaloric effect. HoN nanoparticles are good refrigerant material at low temperature.

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Refrigerant Capacity and Magnetocaloric Effect on LaFe11.1Co0.8Si1.1BX Alloys

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.84-85.667 ◽

2011 ◽

Vol 84-85 ◽

pp. 667-670

Author(s):

Guo Qiu Xie

Keyword(s):

Magnetocaloric Effect ◽

Room Temperature ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Magnetic Entropy ◽

Field Change ◽

Refrigerant Capacity ◽

Structure Phase ◽

Magnetic Field Change ◽

Cubic Structure

In this paper, we report on the structure, magnetic properties and magnetocaloric effect in NaZn13-type LaFe11.1Co0.8Si1.1Bxalloys close to room temperature. The stable NaZn13cubic structure phase (space group isFm-3c) can easily obtained by annealing at 1080 °C for 225 hours. The maximal values of magnetic entropy change for LaFe11.1Co0.8Si1.1Bx(x=0.2, 0.25) were found to be 5.3 and 5.9 J/kg K at Curie temperature for a magnetic field change in 0-1.5 T, respectively. The calculated refrigerant capacity for a field change in 0–1.5 T is about 147 and 107 J/kg K, for LaFe11.1Co0.8Si1.1B0.2and LaFe11.1Co0.8Si1.1B0.25respectively, which is as larger as those of Gd(99.3%) alloy

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The Magentocaloric Effect of Gd5Si2Ge2-XZnX Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.299-300.525 ◽

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.

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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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Modeling the Maximum Magnetic Entropy Change of Doped Manganite Using a Grid Search-Based Extreme Learning Machine and Hybrid Gravitational Search-Based Support Vector Regression

Crystals ◽

10.3390/cryst10040310 ◽

2020 ◽

Vol 10 (4) ◽

pp. 310 ◽

Cited By ~ 2

Author(s):

Sami M. Ibn Shamsah ◽

Taoreed O. Owolabi

Keyword(s):

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Support Vector ◽

Grid Search ◽

Magnetic Entropy ◽

Ionic Model ◽

Crystal Model ◽

Learning Machine ◽

Better Than

The thermal response of a magnetic solid to an applied magnetic field constitutes magnetocaloric effect. The maximum magnetic entropy change (MMEC) is one of the quantitative parameters characterizing this effect, while the magnetic solids exhibiting magnetocaloric effect have great potential in magnetic refrigeration technology as they offer a green solution to the known pollutant-based refrigerants. In order to determine the MMEC of doped manganite and the influence of dopants on the magnetocaloric effect of doped manganite compounds, this work developed a grid search (GS)-based extreme learning machine (ELM) and hybrid gravitational search algorithm (GSA)-based support vector regression (SVR) for estimating the MMEC of doped manganite compounds using ionic radii and crystal lattice parameters as descriptors. Based on the root-mean-square error (RMSE), the developed GSA-SVR-radii model performs better than the existing genetic algorithm (GA)-SVR-ionic model in the literature by 27.09%, while the developed GSA-SVR-crystal model performs better than the existing GA-SVR-lattice model in the literature by 38.34%. Similarly, the developed ELM-GS-crystal model performs better than the existing GA-SVR-ionic model with a performance enhancement of 14.39% and 20.65% using the mean absolute error (MAE) and RMSE, respectively, as performance measuring parameters. The developed models also perform better than the existing models using correlation coefficient as the performance measuring parameter when validated with experimentally measured MMEC. The superior performance of the present models coupled with easy accessibility of the descriptors definitely will facilitate the synthesis of doped manganite compounds with a high magnetocaloric effect without experimental stress.

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