Observation of a Broadened Magnetocaloric Effect in Partially Crystallized Gd60Co40 Amorphous Alloy

To investigate the effect of crystallization treatment on the structure and magnetocaloric effect of Gd60Co40 amorphous alloy, the melt-spun ribbons were annealed at 513 K isothermally for 20, 40 and 60 min. The results indicate that, with increasing annealing time, the Gd4Co3 (space group P63/m) and Gd12Co7 (space group P21/c) phases precipitated from the amorphous precursor in sequence. In particular, in the samples annealed for 40 and 60 min, three successive magnetic transitions corresponding to the phases of Gd4Co3, Gd12Co7 and remaining amorphous matrix were detected, which induced an overlapped broadened profile of magnetic entropy change (|ΔSM|) versus temperature. Under magnetic field changing from 0 to 5 T, |ΔSM| values of 6.65 ± 0.1 kg−1·K−1 and 6.44 ± 0.1 J kg−1·K−1 in the temperature spans of 180–196 K and 177–196 K were obtained in ribbons annealed for 40 and 60 min, respectively. Compared with the fully amorphous alloy, the enhanced relative cooling power and flattened magnetocaloric effect of partially crystallized composites making them more suitable for the Ericsson thermodynamic cycle.

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Achieving better glass-forming ability and magnetocaloric effect in the minor Zr-substituted Gd50Co50 amorphous alloy

International Journal of Modern Physics B ◽

10.1142/s0217979218500856 ◽

2018 ◽

Vol 32 (08) ◽

pp. 1850085

Author(s):

Li Yan Ma ◽

Liang Hua Gan ◽

Lei Xia ◽

JiaZheng Zhang ◽

Ding Ding

Keyword(s):

Amorphous Alloy ◽

Magnetocaloric Effect ◽

Melt Spinning ◽

Magnetic Entropy Change ◽

Thermodynamic Cycle ◽

Entropy Change ◽

Glass Forming Ability ◽

Magnetic Entropy ◽

Glass Forming ◽

Amorphous Ribbons

The glass-forming ability (GFA) and magnetic properties of the minor Zr-substituted Gd[Formula: see text]Co[Formula: see text] amorphous alloy were investigated. The Gd[Formula: see text]Co[Formula: see text]Zr2 amorphous ribbons prepared by melt-spinning show better GFA. With increasing minor Zr addition, the Gd[Formula: see text]Co[Formula: see text]Zr2 amorphous ribbons possessed higher magnetic entropy change peak ([Formula: see text]S[Formula: see text] = 3.9 Jkg[Formula: see text]K[Formula: see text], under 5 T) but lower Curie temperature (T[Formula: see text] = 231 K) than the Gd[Formula: see text]Co[Formula: see text] amorphous alloy. The mechanism for the improved GFA, magnetocaloric effect (MCE) and the decrease in T[Formula: see text] was investigated. Finally, combined with other Gd-based amorphous ribbons, the Gd[Formula: see text]Co[Formula: see text]Zr2 amorphous alloy was employed to construct amorphous composites to achieve a table-like magnetic entropy change profile, which can provide optimal efficiency when utilizing an Ericsson thermodynamic cycle.

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Magnetic and magnetocaloric effect in a stuffed honeycomb polycrystalline antiferromagnet GdInO3

Chinese Physics B ◽

10.1088/1674-1056/ac43a1 ◽

2021 ◽

Author(s):

Yao-Dong Wu ◽

Wei-Wei Duan ◽

Qiu-Yue Li ◽

Yong-Liang Qin ◽

Zhen-Fa Zi ◽

...

Keyword(s):

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Magnetic System ◽

Magnetic Hysteresis ◽

Entropy Change ◽

Cooling Power ◽

Magnetic Entropy ◽

Antiferromagnetic Ordering ◽

Magnetocaloric Properties ◽

The Magnetic Field

Abstract The magnetic and magnetocaloric properties were studied in a stuffed honeycomb polycrystalline antiferromagnet GdInO3. The onset temperature of antiferromagnetic ordering was observed at ~ 2.1 K. Negligible thermal and magnetic hysteresis suggest a reversible magnetocaloric effect (MCE) in the GdInO3 compound. In the magnetic field changes of 0–50 kOe and 0–70 kOe, the maximum magnetic entropy change values are 9.65 J/kg K and 18.37 J/kg K, respectively, near the liquid helium temperature, with the corresponding relative cooling power values of 115.01 J/kg and 211.31 J/kg. The MCE investigation of the polycrystalline GdInO3 serves to illuminate more exotic properties in this frustrated stuffed honeycomb magnetic system.

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Magnetocaloric effect in Sr2FeMoO6/Ag composites

Processing and Application of Ceramics ◽

10.2298/pac1501011h ◽

2015 ◽

Vol 9 (1) ◽

pp. 11-15 ◽

Cited By ~ 24

Author(s):

Mahmoud Hamad

Keyword(s):

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Double Perovskite ◽

Entropy Change ◽

Heat Capacity Change ◽

Cooling Power ◽

Magnetic Entropy ◽

Low Field ◽

Capacity Change ◽

Magnetocaloric Properties

The enhanced low-field magnetocaloric effect was investigated for double perovskite Sr2FeMoO6 - silver (SFMO/Ag) composites with 0, 5 and 10 wt.% of Ag. A phenomenological model was used to predict magnetocaloric properties of SFMO/Ag composites, such as magnetic entropy change, heat capacity change and relative cooling power. It was shown that magnetic entropy change (?S M) peaks of SFMO/Ag span over a wide temperature region, which can significantly improve the global efficiency of the magnetic refrigeration. Furthermore, the ?S M distribution of the SFMO/Ag composites is much more uniform than that of gadolinium. Through these results, SFMO/Ag composite has some potential application for magnetic refrigerants in an extended high-temperature range.

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Magnetocaloric properties of La0.666Sr0.373Mn0.943Cu0.018O3

Processing and Application of Ceramics ◽

10.2298/pac1703225h ◽

2017 ◽

Vol 11 (3) ◽

pp. 225-228 ◽

Cited By ~ 8

Author(s):

Mahmoud Hamad

Keyword(s):

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Cooling Power ◽

Magnetic Entropy ◽

Active Magnetic Regenerator ◽

Magnetocaloric Properties ◽

Magnetic Specific Heat ◽

Prospective Application ◽

Magnetic Regenerator

Magnetocaloric properties of La0.666Sr0.373Mn0.943Cu0.018O3 (LSMCO) perovskite (such as magnetic entropy change, full-width at half-maximum, relative cooling power and magnetic specific heat change) at applied magnetic field of 0.05 T were calculated using the phenomenological model. The results indicate the prospective application of LSMCO due to high magnetocaloric effect near the Curie temperature. Furthermore, the magnetocaloric properties of LSMCO sample are comparable with magnetocaloric properties of MnAs film, La1-xCdxMnO3 and La1.25Sr0.75MnCoO6, and significantly larger than that of Gd1-xCaxBaCo2O5.5 and Ge0.95Mn0.05. It is recommended that magnetocaloric effect of LSMCO can be used as a promising practical material of an apparatus based on the active magnetic regenerator cycle.

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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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Large magnetic entropy change and adiabatic temperature rise of Fe85B12La3 amorphous alloy

Physica B Condensed Matter ◽

10.1016/j.physb.2020.412014 ◽

2020 ◽

Vol 583 ◽

pp. 412014

Author(s):

B.Z. Tang ◽

M.N. Song ◽

L.W. Huang ◽

D. Ding ◽

L. Xia

Keyword(s):

Amorphous Alloy ◽

Temperature Rise ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Adiabatic Temperature ◽

Magnetic Entropy ◽

Adiabatic Temperature Rise

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Magnetic Properties and Magnetocaloric Effect in Gd100-xCox Thin Films

Crystals ◽

10.3390/cryst9060278 ◽

2019 ◽

Vol 9 (6) ◽

pp. 278 ◽

Cited By ~ 1

Author(s):

Mohamed Tadout ◽

Charles-Henri Lambert ◽

Mohammed El Hadri ◽

Abdelilah Benyoussef ◽

Mohammed Hamedoun ◽

...

Keyword(s):

Thin Films ◽

Magnetocaloric Effect ◽

Magnetic Entropy Change ◽

Entropy Change ◽

Magnetic Thin Films ◽

Critical Parameters ◽

Cooling Power ◽

Magnetocaloric Properties ◽

Co Concentration ◽

Key Parameter

We investigated the magnetic and magnetocaloric properties of Gd100-xCox ( x = 40 to 56) thin films fabricated by the sputtering technique. Under an applied field change Δ H = 20 kOe , the magnetic entropy change ( Δ S m ) decreases from 2.64 Jkg−1K−1 for x = 44 to about 1.27 Jkg−1K−1 for x = 56. Increasing the Co concentration from x = 40 to 56 shifts the Curie temperature of Gd100-xCox ( x = 40 to 56) thin films from 180 K toward 337 K. Moreover, we extracted the values of critical parameters Tc, β, γ, and δ by using the modified Arrott plot methods. The results indicate the presence of a long-range ferromagnetic order. More importantly, we showed that the relative cooling power (RCP), which is a key parameter in magnetic refrigeration applications, is strongly enhanced by changing the Co concentration in the Gd100-xCox thin films. Our findings help pave the way toward the enhancement of the magnetocaloric effect in magnetic thin films.

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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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