Cu掺杂ZnO磁性能的实验与理论研究*

摘要

CuxZn1-xO were synthesized via the solid-state reaction route. Ferromagnetism was detected when the Cu per-centage 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+-O2--Cu2+, Cu2+-Vo-Cu2+, Cu2+-Vo+-Cu2+, Cu2+-Vo++-Cu2+ in the CuZnO system, where Vo denoted the vacancy of oxygen. Different bound charge transfer schemes between the Vo and Cu2+ ions were revealed. The origin of the ferromagnetism was determined within the framework of the Cu2+-Vo++-Cu2+ bound magnetic polarons.%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+-Vo++-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+-Vo++-Cu2+束缚磁极化子模型.