Giant low-field reversible magnetocaloric effect at liquid helium temperature of niobium and iron co-substituted EuTiO_(3) compounds  

作　　者：Zhihong Hao Quanyi Liu Huicai Xie Yan Zhang Zhaojun Mo 

机构地区：[1]School of Rare Earth and New Materials Engineering,Ganzhou Innovation Center of Rare Earth Permanent Magnet Material Advanced Manufacturing and Intelligent Equipment Technology,Gannan University of Science and Technology,Ganzhou,341000,China [2]Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou,34119,China [3]School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan,030024,China

出　　处：《Journal of Rare Earths》2024年第4期710-715,共6页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(52171195);Science and Technology Research Project for Education Department of Jiangxi Province(GJJ218509)。

摘　　要：Giant magnetocaloric effect(MCE)materials in the liquid helium temperature region have attracted a lot of attention in the field of low-temperature magnetic refrigeration(MR).In this study,a series of niobium(Nb)and iron(Fe)co-substituted EuTiO_(3) perovskites with cubic structure(space group pm3m)was successfully fabricated,and their magnetic properties as well as cryogenic magnetocaloric effects were investigated in detail.As expected,the introduction of Nb and Fe can significantly modulate the magnetic phase transition and magnetocaloric effect of the EuTiO_(3) compounds.With increasing Fe concentration,two local minima corresponding to the AFM-FM magnetic phase transition near 5.0 K and FM-PM transition near 10 K with no hysteresis in the thermomagnetic curves are observed,which is attributed to an enhancement of FM coupling.At the same time,the gradually widened-ΔSM-T curves and the two peaks with a broad shoulder lead to considerable refrigeration capacity(RC).With the field change ofΔH=2 T,the calculated values of-ΔS_(M)^(max) for the EuTi_(0.9375-x)Nb_(0.0625)Fe_(x)O_(3)(x=0.075,0.1,0.125,0.15)compounds are 24.2,17.6,14.5 and 14.0 J/(kg·K),respectively.The corresponding RC values were calculated to be 144.6,138.3,151.2 and 159 J/kg,respectively.Especially,the values of-ΔS_(M)^(max) for EuTi_(0.8625)Nb_(0.0625)Fe_(0.075)O_(3) are 8.6 and 15.1 J/(kg·K)under low field changes of 0.5 and 1 T,respectively.The giant low-field reversible magnetocaloric effect makes them attractive candidates for magnetic refrigeration in the liquid helium temperature region.

关 键 词：Magnetocaloric effect Refrigeration capacity Magnetic entropy change RAREEARTHS 

分 类 号：TB64[一般工业技术—制冷工程]