Zhang Xingyu, Li Bin, Cheng Jie, Chen Xu, Wang Lining, Miu Zilong, Song Ziwan, Chi Fengfeng, Liu Shengli, Wang Z H
College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications (NJUPT), Nanjing, Jiangsu 210023, People's Republic of China.
J Phys Condens Matter. 2019 Oct 30;31(43):435601. doi: 10.1088/1361-648X/ab2ff8. Epub 2019 Jul 8.
Insulating ferromagnets with high T are required for many new magnetic devices. More complexity arises when strongly correlated 3d ions coexist with strongly spin-orbit coupled 5d ones in a double perovskite. Here, we perform the structural, magnetic, and density functional theory (DFT) study of such double perovskite LaCuIrO. A new P2/n polymorph is found according to the comprehensive analysis of x-ray, Raman scattering and phonon spectrum. The magnetization reveals a weak ferromagnetic (FM) transition at T = 62 K and short range FM order in higher temperature range. A huge coercivity is found as high as H ~ 11.96 kOe at 10 K, which, in combination with the negative trapped field, results in the magnetization reversal in the zero field cooling measurement. The first principle calculations confirm the observed FM state and suggest LaCuIrO of this polymorph is a Mott insulating ferromagnet assisted by the spin-orbit coupling.
许多新型磁器件都需要具有高居里温度（(T_c)）的绝缘铁磁体。当强关联的3d离子与强自旋轨道耦合的5d离子在双钙钛矿中共存时，情况会变得更加复杂。在此，我们对这种双钙钛矿LaCuIrO进行了结构、磁性和密度泛函理论（DFT）研究。通过对X射线、拉曼散射和声子谱的综合分析，发现了一种新的P2/n多晶型物。磁化强度显示在(T = 62K)时存在弱铁磁（FM）转变，并且在较高温度范围内存在短程FM有序。在10K时发现高达(H \approx 11.96 kOe)的巨大矫顽力，这与负俘获场相结合，导致在零场冷却测量中出现磁化反转。第一性原理计算证实了观察到的FM态，并表明这种多晶型的LaCuIrO是一种由自旋轨道耦合辅助的莫特绝缘铁磁体。
