Luo X, Sun Y P, Hu L, Wang B S, Lu W J, Zhu X B, Yang Z R, Song W H
Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
J Phys Condens Matter. 2009 Oct 28;21(43):436010. doi: 10.1088/0953-8984/21/43/436010. Epub 2009 Oct 8.
The magnetocaloric effect (MCE) in an orbital-spin-coupled spinel vanadate MnV(2)O(4) is investigated by magnetization measurement. MnV(2)O(4) has ferrimagnetic ordering occurring at T(C) = 57 K. The maximum magnetic entropy change reaches 14.8 and 24.0 J kg(-1) K(-1) for field changes of 0-2 and 0-4 T, respectively. The maximum adiabatic temperature is about 2.9 K for a magnetic field change of 2 T. Except for the spin entropy change, the observed giant MCE is suggested to be related to the orbital entropy change due to the change of the orbital state of V(3+) induced by an applied magnetic field around T(C).
通过磁化测量研究了轨道 - 自旋耦合尖晶石钒酸盐MnV₂O₄中的磁热效应（MCE）。MnV₂O₄在居里温度TC = 57 K时发生亚铁磁有序。对于0 - 2 T和0 - 4 T的磁场变化，最大磁熵变分别达到14.8和24.0 J kg⁻¹ K⁻¹。对于2 T的磁场变化，最大绝热温度约为2.9 K。除了自旋熵变外，观察到的巨大磁热效应被认为与在居里温度附近由于外加磁场引起的V³⁺轨道状态变化导致的轨道熵变有关。
