摘要
采用标准固相反应法制备了La0.45Ca0.55Mn1-xVxO3(x=0.00,0.06,0.10,0.12)多晶样品。通过XRD、ρ-T曲线、M-T曲线和ρ-T拟合曲线,研究了Mn位V5+离子掺杂对体系的电荷有序相及输运性质的影响。实验结果表明:随着V5+离子的掺杂量的增加,电荷有序相(CO)逐渐削弱,当x=0.10时,CO相基本融化但还有部分残留,当x=0.12时CO相完全融化;对低掺杂(x=0.00,0.06)样品,表现出复杂磁相:随温度降低,发生顺磁-电荷有序-反铁磁相变,40 K附近,在反铁磁背景下产生再入型自旋玻璃态;随掺杂量增加,体系的电阻率逐渐减小,当掺杂量x≥0.10时,样品发生金属-绝缘体相变,其相变温度随着掺杂量的增加而向高温移动。对于金属型导电机制满足自旋波散射和电-磁子之间的散射,而绝缘体导电机制有两种情况:x≤0.10的样品满足变程跃迁模型ρ=ρ0exp(T0/T)1/4,x=0.12的样品则满足小极化子绝热最近邻跃迁模型ρ=ATexp(Eα/κBT),通过掺杂实现了从变程跃迁到绝热小极化子最近邻跃迁。
The polycrystalline samples of La0.45Ca0.55Mn1-xVxO3(x=0.00,0.06,0.10,0.12) were prepared by the standard solid-state reaction.Influence of V doping at Mn-site on transport properties and charge-ordering phase was researched through the measurements of XRD,ρ-T curve and M-T curve.The results showed that charge ordering became weaker gradually with the increase of V doping level and melted completely when x=0.12;samples of low V doping(x=0.00,0.06) exhibited complex magnetic phases,the paramagnetism-charge o...
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2010年第3期345-351,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金重点项目(19934003)
国家重大研究计划课题(2007CB925001)
安徽省教育厅自然科学研究项目(KJ2009B281Z)
安徽省教育厅自然科学研究重大项目(ZD2007003-1)
安徽省教育厅自然科学研究重点项目(KJ2008A26ZC)和安徽省教育厅自然科学研究重点项目(KJ2008A19ZC)资助
