Cu掺杂对Fe/Mo双钙钛矿居里温度的影响

研究了双钙钛矿结构化合物Sr2FeMoO6中Fe位的Cu2+离子替代效应,样品中Cu2+离子替代Fe3+离子没有引起结构变化,但导致样品B位离子有序度降低.并且随Cu2+离子的掺入,室温下样品的磁化强度迅速下降.而居里温度TC随Cu2+的掺入有所上升,因此认为Cu2+离子的掺入破坏了Fe3+-Mo5+反铁磁耦合,抑制了样品的原有铁磁性,促使Mo5+向Mo6+的转变和Fe3+向Fe2+的转变引起Fe/Mo反位无序的增加,形成了Fe3+-Fe2+反铁磁耦合团簇.

The effect on Curie temperature of Cu2+ ions doping in double perovskites Sr2FeMoO6 polycrystals

The effect of substituting Fe~(3+) by Cu~(2+) of double perovskites polycrystals Sr_2Fe_(1-x)Cu_xMoO_6 has been investigated.The main phase of Sr_2FeMoO_6 has not been changed,but the order of the ions at B sites is reduced.Magnetization of the sample declines rapidly with Cu~(2+) ions' doping under room temperature and the Curie temperature rises.It's concluded that Cu~(2+) ions destroy the antiferromagnetic coupling of Fe~(3+)-Mo~(5+) in the system strongly,suppress the ferromagnetism of Sr_2FeMoO_6,urge Mo~(5+) ions to transfer into Mo~(6+) ions and Fe~(3+) ions into Fe~(2+) ions,induce the increasing of Fe/Mo anti-site disorder and form the cluster of Fe~(3+)-Fe~(2+) antiferromagnetic coupling.