摘要
为了解决在空气条件下热处理温度和次数对含有B位空位锰氧化物La0.75Sr0.25Mn0.95Δ0.05O3中氧含量影响的物理问题,采用改进的溶胶凝胶法,成功制备了名义成分为La0.75Sr0.25Mn0.95Δ0.05O3的钙钛矿锰氧化物材料,先后对样品在973,107 3,127 3,147 3K进行了4次热处理,对其结构和磁性进行了研究.结果表明,经973K热处理后样品晶粒表面明显缺氧,导致其中存有碳元素;经过后3次热处理,样品的氧含量逐渐增加,从正分到过剩.结合晶体缺陷热平衡理论,氧含量过剩时,实际上形成了B位含有空位的AB1-Δ-zO3型钙钛矿结构.
The effect of heat treatment temperature and times in atmosphere on the content of the vacancy at the B sites in La0.75Sr0.25Mn0.95Δ0.05O3,were investigated.Nominal composition La0.75Sr0.25Mn0.95-Δ0.05O3 have been prepared successfully by the sol-gel method,subjected calcination at temperature TCal=973,107 3,127 3,and 147 3K,successively.X-ray diffraction and magnetic measurement results indicates that there is C element on crystallite surface after heat treatment at 973 Ksince obviously insufficient the oxygen content;the oxygen content increase gradually after further heat treatments,from sufficient toexcessive,and then the content of vacancy at the B sites.According to the theory about crystal thermal equilibrium,the sample actually formAB1-Δ-zO3 perovskite structure as oxygen content is excessive,which contains two kinds of vacancy at B the sites.
出处
《河北大学学报（自然科学版）》
CAS
北大核心
2014年第6期585-590,596,共7页
Journal of Hebei University(Natural Science Edition)
基金
国家自然科学基金资助项目(11174069)
河北省科技厅基金资助项目(A2013205101)
贵州省教育厅自然科学重点研究项目(2013174)
六盘水师范学院高层次人才科研启动基金
关键词
钙钛矿锰氧化物
空位
晶体结构
溶胶凝胶法
热处理
Perovskite manganite
vacancy
crystal structure
sol-gel method
heat treatment
