J. Mater. Sci. Technol. ›› 2023, Vol. 146: 168-176.DOI: 10.1016/j.jmst.2022.10.066

• Research Article • Previous Articles     Next Articles

Giant low-field magnetocaloric effect in ferromagnetically ordered Er1-xTmxAl2 (0 ≤ x ≤ 1) compounds

Shuxian Yanga,b, Xinqi Zhenga,*, Dingsong Wanga, Juping Xuc,d, Wen Yinc,d, Lei Xia,e, Chaofan Liua, Jun Liuf, Jiawang Xug,b, Hu Zhanga, Zhiyi Xub,h, Lichen Wangh,i, Yihong Yaoa, Maosen Zhanga, Yichi Zhanga, Jianxin Shena, Shouguo Wanga,e,*, Baogen Shenb,h,i   

  1. aSchool of Materials Science and Engineering, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    bBeijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences & University of Chinese Academy of Sciences, Beijing 100190, China;
    cInstitute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;
    dSpallation Neutron Source Science Center, Dongguan 523803, China;
    eSchool of Materials Science and Engineering, Anhui University, Hefei 230601, China;
    fDepartment of Energy and Power Engineering, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China;
    gSongshan Lake Materials Laboratory, Dongguan 523808, China;
    hGanjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, China;
    iNingbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
  • Received:2022-07-31 Revised:2022-10-19 Accepted:2022-10-20 Published:2023-05-20 Online:2023-05-15
  • Contact: * E-mail addresses: zhengxq@ustb.edu.cn (X. Zheng), sgwang@ustb.edu.cn (S. Wang)

Abstract: Magnetocaloric material is the key working substance for magnetic refrigerant technology, for which the low-field and low-temperature magnetocaloric effect (MCE) performance is of great importance for practical applications at low temperatures. Here, a giant low-field magnetocaloric effect in ferromagnetically ordered Er1-xTmxAl2 (0 ≤ x ≤ 1) compounds was reported, and the magnetic structure was characterized based on low-temperature neutron powder diffraction. With increasing Tm content from 0 to 1, the Curie temperature of Er1-xTmxAl2 (0 ≤ x ≤ 1) compounds decreases from 16.0 K to 3.6 K. For Er0.7Tm0.3Al2 compound, it showed the largest low-field magnetic entropy change (-ΔSM) with the peak value of 17.2 and 25.7 J/(kg K) for 0-1 T and 0-2 T, respectively. The (-ΔSM)max up to 17.2 J/(kg K) of Er0.7Tm0.3Al2 compound for 0-1 T is the largest among the intermetallic magnetocaloric materials ever reported at temperatures below 20 K. The peak value of adiabatic temperature change (ΔTad)max was determined as 4.13 K and 6.87 K for 0-1 T and 0-2 T, respectively. The characteristic of second-order magnetic transitions was confirmed on basis of Arrott plots, the quantitative criterion of exponent n, rescaled universal curves, and the mean-field theory criterion. The outstanding low-field MCE performance with low working temperatures indicates that Er1-xTmxAl2 (0 ≤ x ≤ 1) compounds are promising candidates for magnetic cooling materials at liquid hydrogen and liquid helium temperatures.

Key words: Magnetocaloric effect, Low field magnetocaloric effect, Magnetic structure, RAl2 compounds