A series of new octanuclear Ln8 clusters: magnetic studies reveal a significant cryogenic magnetocaloric effect and slow magnetic relaxation

2019 ◽  
Vol 43 (3) ◽  
pp. 1617-1625 ◽  
Author(s):  
Ling-Fei Li ◽  
Wei-Wei Kuang ◽  
Yi-Ming Li ◽  
Li-Li Zhu ◽  
Yun Xu ◽  
...  

A series of new octanuclear Ln8 clusters. Magnetically, Gd8 exhibited a significant magnetocaloric effect and a magnetic entropy change is 32.49 J K−1 kg−1 for a field of 7 T at 2 K, while Dy8 exhibited a frequency dependent slow relaxation of magnetization at a zero applied direct current magnetic field.

2015 ◽  
Vol 44 (2) ◽  
pp. 468-471 ◽  
Author(s):  
Han Li ◽  
Wei Shi ◽  
Zheng Niu ◽  
Jing-Min Zhou ◽  
Gang Xiong ◽  
...  

Two 3d–4f clusters were reported: Gd3Fe2 possesses significant magnetic entropy change and slow magnetic relaxation is observed in Dy3Fe2.


2011 ◽  
Vol 685 ◽  
pp. 311-315
Author(s):  
Zhi Zeng ◽  
Xue Zhen Wang ◽  
Jian Huang ◽  
Jie Xiang ◽  
Xue Ling Hou

Gd5Si2Ge2-based alloys can exhibit a giant magnetocaloric effect (GMCE) which gives them the potential use in the cooling technologies[1].Through this studies, it can be found that the purity of Gd had a great impact on the magnetocaloric effect in Gd5Si2-xGe2-xZn2x alloys. When 3N Gd used and 2x=0.01, Gd5Si2-xGe2-xZn2x around the curie point of 280k get the maximum magnetic entropy change of 14.0 J/(Kg.K) under the external magnetic field change from 0 to 1T, but when 2N Gd used and 2x=0.05, Gd5Si2-xGe2-xZn2x around the curie point of 284.2k under the external magnetic field change 1T get the maximum magnetic entropy change 6.65 J/(Kg.K).


2021 ◽  
Vol 63 (10) ◽  
pp. 1551
Author(s):  
E.M. Ahmed ◽  
H.R. Alamri ◽  
S.M. Elghnam ◽  
O. Eldarawi ◽  
T.E. Tawfik ◽  
...  

Low magnetic field magnetocaloric (MC) properties of La1-xSrxCoO3 (x=0.3 and 0.5) near phase transition from a ferromagnetic to a paramagnetic state were investigated. It is shown that the change of Sr content allows MC effect in La1-xSrxCoO3 to be tunable, which is more practical for construction of MC refrigeration. MC properties of the x=0.5 sample are significantly greater than that of the x=0.3 one. Furthermore, the results show that MC properties of La1-xSrxCoO3 samples are significantly larger, and comparable with some MC properties of many materials like Gd1-xCaxBaCo2O5.5 and Ge0.95Mn0.05. Keywords: magnetocaloric effect, La1-xSrxCoO3, magnetic entropy change.


2013 ◽  
Vol 683 ◽  
pp. 56-59 ◽  
Author(s):  
Jian Hua Lin ◽  
Shan Dong Li ◽  
Li Li Wang ◽  
Jie Qiu ◽  
Zhi Yi Cai ◽  
...  

The room-temperature magnetocaloric effect (MCE) of Cox(MnSb)1-x (x=0.07, 0.15, 0.24) alloys has been investigated. It is revealed that the Curie temperature TC and the magnetic entropy change ΔSM are sensitive to the Co content x. When x=0.15, the MCE of Co0.15(MnSb)0.85 alloy is optimal with ΔSM=1.8 J/kg.K at 324 K under an applied magnetic field of 3 T. A second-order phase transformation occurs around TC, and the magnetic hysteresis loss thermal lag is negligible. These features demonstrate that Co0.15(MnSb)0.85 alloy is a promising room-temperature magnetocaloric materials.


RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75562-75569 ◽  
Author(s):  
K. P. Shinde ◽  
S. H. Jang ◽  
M. Ranot ◽  
B. B. Sinha ◽  
J. W. Kim ◽  
...  

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.


2011 ◽  
Vol 84-85 ◽  
pp. 667-670
Author(s):  
Guo Qiu Xie

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


2019 ◽  
Vol 43 (33) ◽  
pp. 12941-12949 ◽  
Author(s):  
Wen-Min Wang ◽  
Li Zhang ◽  
Xian-Zhen Li ◽  
Li-Yuan He ◽  
Xin-Xin Wang ◽  
...  

A family LnIII4 clusters were successfully synthesized and structurally characterized. Magnetic studies show that Gd4 cluster displays magnetic refrigeration, while Dy4 cluster demonstrates two distinct slow magnetic relaxation processes.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 310 ◽  
Author(s):  
Sami M. Ibn Shamsah ◽  
Taoreed O. Owolabi

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.


RSC Advances ◽  
2017 ◽  
Vol 7 (49) ◽  
pp. 30763-30769 ◽  
Author(s):  
Radovan Herchel ◽  
Kamil Kotrle ◽  
Zdeněk Trávníček

A general correlation for Gd(iii) complexes showing the magnetocaloric effect was proposed.


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