Nb掺杂对双钙钛矿化合物居里温度的影响

The Effect of Substituting Nb on the Curie Temperature of Double-perovskite Compounds

研究了双钙钛矿结构化合物Sr2FeMo1-xNbxO6中Mo位的Nb替代效应,发现了在x≤0.40的范围内Nb替代Mo,没有引起样品的结构的变化,但导致了样品的B位离子有序度的降低,抑制了Sr2FeMoO6的铁磁性,使样品的居里温度随Nb的掺入而降低.讨论发现,随着Nb的掺入,Fe3+之间的铁磁性排列的减少,反铁磁性排列的增加是产生上述结果的主要原因.

The effect of substituting Mo by Nb of double perovskite compounds Sr_2FeMo_(1-x)Nb_xO_6 has been investigated.The substitution of Nb for Mo in the range of 0≤x≤0.40 does not undergo the structural transition,but reduces the order of the ions at B sites,suppresses the ferromagnetism of Sr_2FeMoO_6 and lowers the Curie temperature T_c of the compounds.Reducing ferromagnetic coupling and increasing the anti-ferromagnetic coupling between Fe^(3+) by the substitution of non-magnetic Nb^(5+) ion are suggested to explain the expermental results.