Cr,Ce共掺杂调控V_(3)O_(4)半金属材料自旋极化机制的第一性原理研究

Study on first-principles of the effect of Cr and Ce co-doping on spin polarization in semimetal V_(3)O_(4)

如何提高V_(3)O_(4)材料的居里温度,是此半金属材料应用于自旋半导体器件所面临的一个重要问题.针对此问题,本论文采用第一性原理计算研究了不同位置的Cr和Ce共掺杂对V_(3)O_(4)自旋极化的影响机制.计算结果表明相比于理想V_(3)O_(4),Cr和Ce共掺杂降低了V_(3)O_(4)的自旋极化率和总磁矩.但是当Cr和Ce共掺杂都占据A位,都占据B位,以及分别占据B和A位时,其铁磁态稳定性和居里温度都会有极大提高,其中Cr和Ce共掺杂都占据A位时可以最大化提高其铁磁稳定性和居里温度.以上研究为提高V_(3)O_(4)的铁磁稳定性和居里温度提供了有效途径,进一步促进了半金属V_(3)O_(4)材料在自旋电子学中的应用.

Improving the Curie temperature of V_(3)O_(4) is a key problem to the application of this semimetal material in semiconductor spintronics.In this paper,the mechanism of the effect of the Cr and Ce co-doping on the spin polarization is investigated using the first-principles calculations.The results reveal that,compared with ideal V_(3)O_(4),Cr and Ce co-doping lowers the spin polarization degree and total magnetic moment.However,when Cr and Ce dopants both at A sites,both at B sites,as well as at B and A sites,the stability of ferromagnetic state and the Curie temperature are both increased.Cr and Ce dopants both at A sites can best improve the ferromagnetic state and the Curie temperature.This study provides the theoretical guidance and method for improving stability of ferromagnetic state and the Curie temperature of V_(3)O_(4),which promotes the applications of half-metal V_(3)O_(4) in spintronics.