摘要
We present a study on the magnetocaloric properties of a CaBaCo_(4)O_(7) polycrystalline cobaltite along with research on the nature of magnetic phase transition.The magnetization as a function of temperature identifies the ferrimagnetic to paramagnetic transition at a Curie temperature of 60 K.Moreover,a Griffiths-like phase is confirmed in a temperature range above T_(C).The compound undergoes a crossover from the first to second-order ferrimagnetic transformation,as evidenced by the Arrott plots,scaling of the universal entropy curve,and field-dependent magnetic entropy change.The maximum of entropy change is 3 J/kg⋅K for ΔH=7 T at T_(C),and a broadening of the entropy peak with increasing magnetic field indicates a field-induced transition above T_(C).The analysis of the magnetic entropy change using the Landau theory reveals the second-order phase transition and indicates that the magnetocaloric properties of CaBaCo_(4)O_(7) are dominated by the magnetoelastic coupling and electron interaction.The corresponding values of refrigerant capacity and relative cooling power are estimated to be 33 J/kg and 42 J/kg,respectively.
作者
Tina Raoufi
何金城
王彬彬
刘恩克
孙阳
Tina Raoufi;Jincheng He;Binbin Wang;Enke Liu;Young Sun(Beijing National Laboratory for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Center of Quantum Materials and Devices,Chongqing University,Chongqing 401331,China)
基金
Project supported by the National Natural Science Foundation of China (Grant No.51725104)
Beijing Natural Science Foundation (Grant No.Z180009)。
