Bi0.5Ca0.5Mn1-xCoxO3体系中的电荷有序和相分离

利用固相反应法制备了Bi_0.5Ca_0.5Mn_1-xCo_xO₃(0≤x≤0.12)系列多晶样品.研究了Co掺杂对Bi_0.5Ca_0.5MnO₃电荷有序的影响.结果表明,Co掺杂导致电荷有序相逐渐融化、铁磁相互作用的增强;当x≥0.08时,电荷有序转变峰完全消失,但残留的反铁磁电荷有 关键词： 钙钛矿锰氧化物 电荷有序 团簇玻璃 相分离

Charge order and phase separation in Bi0.5 Ca0.5 Mn1-x Cox O3 system

Polycrystalline Bi_0.5Ca_0.5Mn_1-xCo_xO₃(0≤ x≤0.12) samples are synthesized by using the solid-state reaction. The effects of Co-doping on charge order of Bi_0.5Ca_0.5MnO₃ are studied. The results show that Co doping leads to the melting of the charge order and the enhancement of the ferromagnetic correlation. For x≥0.08, the charge order transition is completely suppressed; however, there are still remaining antiferromagnetic domains inside the system. The phase separation or the coexistence of the charge order and ferromagnetic phase induced by Co-doping plays an important role in the low temperature properties for the system. Moreover, unlike in the case of rare-earth manganites, Co is more efficient to suppress charge order of Bi_0.5Ca_0.5MnO₃ than Cr.