摘要
The magnetic ground state switching between antiferromagnetic(AFM)and ferromagnetic(FM)states in EuTiO_(3)provides the feasibility of regulating its magnetic properties and magnetocaloric effect.First-principles calculations demonstrate that the magnetic ground states for EuTi_(0.875)Nb_(0.0625)Al_(0.0625)O_(3),EuTi_(0.8125)Nb_(0.125)Al_(0.)0_(625)O_(3),and EuTi_(0.75)Nb_(0.125)Al_(0.125)O_(3)are FM coupling.Experimental results also exhibit the FM coupling domination in these compounds,accompanied by a significantly enhanced low magnetic field magnetocaloric effect.The maximum magnetic entropy change of all the samples surpasses15 J kg^(-1)K^(-1)with a field change of 1 T.which is 1.4 times as large as that of bulk EuTiO_(3).Especially,the maximum refrigerating capacity for EuTi_(0.8125)Nb_(0.125)Al_(0.0625)O_(3)compound is evaluated to be 88.1 J kg^(-1),more than three times of that of EuTiO_(3).The remarkable magnetocaloric performances prove Nb and Al co-substituted EuTiO_(3)compounds to be competitive candidates for magnetic refrigeration in the liquid helium temperature regime.
基金
supported financially by National Key R&D Program of China(No.2021YFB3501204)
the National Science Fund for Distinguished Young Scholars(No.51925605)
the National Natural Science Foundation of China(Nos.52171195 and 52171054)
the Basic Frontier Scientific Research Program of Chinese Academyof Sciences From 0 to 1 Original Innovation Project(No.ZDBS-LYJSC017)
the Key Research Program of Chinese Academy of Sciences(No.ZDRW-CN-2021-3)。
