钴掺杂二氧化锡纳米粉的光致发光和磁学性质

Photoluminescence and magnetic properties of cobalt doped SnO_2 nano-powder

研究了钴掺杂对二氧化锡纳米粉的光致发光性质和磁学性质的影响,发现钴掺杂对发光带的位置影响很小,但紫外发光带与蓝色发光带的强度之比随掺杂含量的增加而下降.当钴掺杂含量达到0.02时,样品中的铁磁性被完全破坏.讨论了样品中的磁相互作用的机理,认为掺杂离子的不均匀分布、自旋极化子与掺杂离子之间的耦合都可能导致反铁磁性的相互作用,这种反铁磁性的作用破坏了铁磁性.

The influence of cobalt dopant on the photoluminescence and magnetic properties of SnO_2 nano-powder is studied in detail. The cobalt dopant has little influence on the photoluminescence peaks＇ positions. However,the intensity ratio of ultra-violet to blue emission band is reduced with the increase of cobalt doping. The ferromagnetism is absolutely absent when the cobalt dopant level reaches 0.02. The magnetic interaction mechanism is discussed. Due to the non-uniform distribution of doping,and the coupling between the polarized spin on defects and the dopants,the anti-ferromagnetic interaction destroys the ferromagnetism.