采用第一性原理计算方法,研究了双层钙钛矿氧化物Ba2CoOsO6的晶体结构、电子结构及自旋-轨道耦合作用(SOC)对其电磁性质的影响,并分析电子结构和自旋-轨道耦合作用对其宏观物理性质的影响.结果表明:Ba2CoOsO6为反铁磁窄带隙半导体,存在Os1/Co1反位缺陷;电子结构的分析结果证实了Ba2CoOsO6的电荷分布为Ba2+2Co2+Os6+O2-6,确定了2价Co离子和6价Os离子的存在;SOC的存在减小了Co离子和Os离子的自旋磁矩,同时减小了带隙;根据第一性原理计算结果可知,自旋-轨道耦合作用对电子结构和电磁性质的影响不可忽视,相较于其他方法,该方法计算值与试验分析结果更接近,也验证了理论计算的准确性.
Abstract
The crystal structure, electronic structure and the effect of spinorbit coupling (SOC) on the magnetic and electronic properties of double perovskite Ba2CoOsO6 were systematically investigated by firstprinciples calculations. Through the coupling analysis of electron structure and spin orbit, the influence on the macroscopic physical properties was discussed. The results show that Ba2CoOsO6 is antiferromagnetic semiconductor material with narrow band gap and disordered Os1/Co1 defects. The electronic structure analysis confirms that the charge combination of Ba2CoOsO6 is Ba2+2Co2+Os6+O2-6, which verifies the existence of Co2+ and Os6+. The spin magnetic moment of Co and Os ions is decreased by SOC, and the band gap is narrowed. The results of firstprinciples calculations show that the effect of spinorbit coupling on electronic structure and electromagnetic properties can not be ignored. Compared with other methods, the calculated values are closer to the results of experimental analysis, which can verify the theoretical calculation.
关键词
Ba2CoOsO6 /
双层钙钛矿 /
自旋-轨道耦合 /
第一性原理计算 /
反铁磁耦合 /
半导体
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Key words
Ba2CoOsO6 /
double perovskite /
spinorbit coupling /
firstprinciples calculation /
antiferromagnetic coupling /
semiconductor
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参考文献
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脚注
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基金
国家自然科学基金资助项目(21301075,21901086); 江苏大学高级人才基金资助项目(12JDG096,19JDG017)
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