Pressure-induced metallic ferromagnetism in antiferromagnetic insulator LaMnAsO

National Conference on Theory of Magnetism

Tang, Huaibao^1 ; Li, Guang^1 ; Yang, Qun^1 ; Zuo, Xueqing^1 ; Zhang, Haijun^1 ; Liu, Dayong^2

School of Physics and Materials Science, Anhui University, Hefei

230039, China^1

Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei, ANHUI

230031, China^2

关键词: Antiferromagnetic insulators;    Antiferromagnetics;    Critical pressures;    Density of state;    First-principles calculation;    High spin state;    Metal transition;    Two-state devices;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/827/1/012013/pdf
DOI  :  10.1088/1742-6596/827/1/012013

来源: IOP

【 摘 要 】

Based on the first-principles calculations, we investigate the effects of the hydrostatic pressure on the layered oxypnictide LaMnAsO, and predict that it undergoes a transition from a G-type antiferromagnetic (AFM) insulator to a ferromagnetic (FM) metal at the critical pressure Pc∼ 18.0 GPa, accompanied by a high-spin state with (mMn= 2.65 μB) to low-spin mMn= 1.63 μBtransition, or magnetic moment collapse. Our calculations identify that it is the hydrostatic pressure that collapses the G-type AFM gap, and the large density of state (DOS) around Fermi level stabilizes the FM metallic phase due to the Stoner instability. The pressure-induced AFM insulator to FM metal transition opens up the possibility of two state device applications in the oxypnictide LaMnAsO compound.