Cu掺杂ZnO磁性能的实验与理论研究

采用固相反应法制备了Cu掺杂ZnO样品.在室温下Cu含量3%的样品在室温下表现为铁磁性.样品为n型半导体,载流子的浓度为1015cm-3.利用密度泛函理论(DFT+U)计算了CuZnO体系的Cu2+—O2-—Cu2+,Cu2+—Vo—Cu2+,Cu2+—Vo+—Cu2+,Cu2+—V++o—Cu2+磁交换耦合作用,给出了不同束缚电荷的氧空穴Vo与Cu2+离子之间的超交换机理,提出了CuZnO体系中铁磁性机理为Cu2+—V++o—Cu2+束缚磁极化子模型.

Magnetic properties of the Cu-doped ZnO：experiments and theory

Cu_x Zn_1-xO were synthesized via the solid-state reaction route. Ferromagnetism was detected when the Cu percentage was bigger than 3%. The compounds were found to be the N-type semiconductors with a carrier concentration of 10¹⁵ cm^-3. The DFT+U method was employed to calculate the magnetic exchange coupling of the Cu²⁺–O^2-–Cu²⁺, Cu²⁺–V_o–Cu²⁺, Cu²⁺–V_o⁺–Cu²⁺, Cu²⁺–V_o⁺⁺–Cu²⁺ in the CuZnO system, where V_o denoted the vacancy of oxygen. Different bound charge transfer schemes between the V_o and Cu²⁺ ions were revealed. The origin of the ferromagnetism was determined within the framework of the Cu²⁺–V_o⁺⁺–Cu²⁺ bound magnetic polarons.
Keywords： CuZnO solid-state reaction ferromagnetism bound magnetic polarons