本文使用在位库仑作用、局域密度近似下的投影缀加平面波方法,计算了钙钛矿材料锆酸锶（SrZrO3）正交相掺Co前后的晶体结构、电子能带结构及掺Co后的磁性质.结果表明：当Co Co之间的间距L为0.4097 nm,即最近邻,且体系为铁磁构型时对应...本文使用在位库仑作用、局域密度近似下的投影缀加平面波方法,计算了钙钛矿材料锆酸锶（SrZrO3）正交相掺Co前后的晶体结构、电子能带结构及掺Co后的磁性质.结果表明：当Co Co之间的间距L为0.4097 nm,即最近邻,且体系为铁磁构型时对应的总能最低,表明 Co 掺杂进入钙钛矿 B位后,容易出现 Co 离子的团簇聚集,出现铁磁性；电子能带结构图显示Co部分替代Zr4＋后变为 Co4＋（3d5）,相对于标准化合价的 Co3＋（3d6）,有一条空的d轨道未占据,又由于掺杂Co后其d轨道与近邻O 的p轨道有强烈杂化,有部分Co的d轨道及O 的部分p轨道越过价带进入带隙,在0~2.60 eV之间,自旋向上出现3条Co 3d能带,自旋向下出现7条 Co 3d能带,且导带底向低能移动；部分Co离子替代钙钛矿B位的Zr4＋后,体系出现磁性,由于 Co 离子形式化合价为＋3,替代 Zr4＋后,这种空穴掺杂将在价带顶引入空的掺杂能级；态密度结果表明该能级为 Co4＋离子部分空的d轨道,通过 O 的p轨道,造成体系中Co3＋、Co4＋离子的出现,而它们之间的双交换耦合使得体系出现铁磁性.展开更多
A theoretical study on discrete vortex bound states is carried out near a vortex core in the presence of a van Hove singularity(VHS) near the Fermi level by solving Bogoliubov–de Gennes(Bd G) equations. When the VHS ...A theoretical study on discrete vortex bound states is carried out near a vortex core in the presence of a van Hove singularity(VHS) near the Fermi level by solving Bogoliubov–de Gennes(Bd G) equations. When the VHS lies exactly at the Fermi level and also at the middle of the band, a zero-energy state and other higher-energy states whose energy ratios follow integer numbers emerge. These discrete vortex bound state peaks undergo a splitting behavior when the VHS or Fermi level moves away from the middle of the band. Such splitting behavior will eventually lead to a new arrangement of quantized vortex core states whose energy ratios follow half-odd-integer numbers.展开更多
文摘本文使用在位库仑作用、局域密度近似下的投影缀加平面波方法,计算了钙钛矿材料锆酸锶（SrZrO3）正交相掺Co前后的晶体结构、电子能带结构及掺Co后的磁性质.结果表明：当Co Co之间的间距L为0.4097 nm,即最近邻,且体系为铁磁构型时对应的总能最低,表明 Co 掺杂进入钙钛矿 B位后,容易出现 Co 离子的团簇聚集,出现铁磁性；电子能带结构图显示Co部分替代Zr4＋后变为 Co4＋（3d5）,相对于标准化合价的 Co3＋（3d6）,有一条空的d轨道未占据,又由于掺杂Co后其d轨道与近邻O 的p轨道有强烈杂化,有部分Co的d轨道及O 的部分p轨道越过价带进入带隙,在0~2.60 eV之间,自旋向上出现3条Co 3d能带,自旋向下出现7条 Co 3d能带,且导带底向低能移动；部分Co离子替代钙钛矿B位的Zr4＋后,体系出现磁性,由于 Co 离子形式化合价为＋3,替代 Zr4＋后,这种空穴掺杂将在价带顶引入空的掺杂能级；态密度结果表明该能级为 Co4＋离子部分空的d轨道,通过 O 的p轨道,造成体系中Co3＋、Co4＋离子的出现,而它们之间的双交换耦合使得体系出现铁磁性.
基金the National Natural Science Foundation of China (Grant No. 11804154)the Scientific Research Foundation of NJIT (Grant Nos. YKJ201853 and CKJA201807)。
文摘A theoretical study on discrete vortex bound states is carried out near a vortex core in the presence of a van Hove singularity(VHS) near the Fermi level by solving Bogoliubov–de Gennes(Bd G) equations. When the VHS lies exactly at the Fermi level and also at the middle of the band, a zero-energy state and other higher-energy states whose energy ratios follow integer numbers emerge. These discrete vortex bound state peaks undergo a splitting behavior when the VHS or Fermi level moves away from the middle of the band. Such splitting behavior will eventually lead to a new arrangement of quantized vortex core states whose energy ratios follow half-odd-integer numbers.
