J. Mater. Sci. Technol. ›› 2022, Vol. 118: 128-135.DOI: 10.1016/j.jmst.2022.02.005

• Research Article • Previous Articles     Next Articles

Enhanced low-field magnetocaloric effect in Nb and Al co-substituted EuTiO3 compounds

Huicai Xiea,b, Wenxia Suc, Haiming Luc, Zhaojun Moa,*(), Dunhui Wangc, Hao Suna, Lu tiana, Xinqiang Gaoa, Zhenxing Lia, Jun Shena,b,d,*()   

  1. aGanjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China
    bFaculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China
    cNational Laboratory of Solid State Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, School of Physics, Nanjing University, Nanjing 210093, China
    dKey Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2021-11-16 Revised:2022-01-30 Accepted:2022-02-09 Published:2022-08-10 Online:2022-02-25
  • Contact: Zhaojun Mo,Jun Shen
  • About author:jshen@mail.ipc.ac.cn (J. Shen).
    * Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China. E-mail addresses: mozhaojun@gia.cas.cn (Z. Mo),

Abstract:

The magnetic ground state switching between antiferromagnetic (AFM) and ferromagnetic (FM) states in EuTiO3 provides the feasibility of regulating its magnetic properties and magnetocaloric effect. First-principles calculations demonstrate that the magnetic ground states for EuTi0.875Nb0.0625Al0.0625O3, EuTi0.8125Nb0.125Al0.0625O3, and EuTi0.75Nb0.125Al0.125O3 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 surpasses 15 J kg-1 K-1 with a field change of 1 T, which is 1.4 times as large as that of bulk EuTiO3. Especially, the maximum refrigerating capacity for EuTi0.8125Nb0.125Al0.0625O3 compound is evaluated to be 88.1 J kg-1, more than three times of that of EuTiO3. The remarkable magnetocaloric performances prove Nb and Al co-substituted EuTiO3 compounds to be competitive candidates for magnetic refrigeration in the liquid helium temperature regime.

Key words: Magnetocaloric effect, Europium titanate (EuTiO3), Ferromagnetic, Magnetic refrigeration