La_(1-x)Pr_xCrO_3纳米晶的结构和磁性质  

STRUCTURAL AND MAGNETIC PROPERTIES OF La_(1-x)Pr_xCrO_3 NANOCRYSTALLINE SYNTHESIZED BY ASOL-GEL PROCESS

作　　者：郑保忠[1] 张建武[1] 浦其荣[2] 张增明[2] 丁泽军[1] 

机构地区：[1]中国科技大学物理系,合肥230001 [2]中国科技大学天文与应用物理系,合肥230026

出　　处：《低温物理学报》2007年第3期184-187,共4页Low Temperature Physical Letters

基　　金：教育部留学回国人员启动基金(2004)资助的课题;安徽省自然科学基金(项目编号:070416235)资助的课题~~

摘　　要：我们用柠檬酸溶胶凝胶法成功制备了Pr掺杂La1-xPrxCrO3（x=0-0.6）纳米晶.在硝酸盐溶液中加入柠檬酸作为螯合剂,乙二醇为分散剂,得到干凝胶并在烧结温度为600℃时获得纯相钙钛矿结构纳米晶粉体,颗粒直径大约为40nm且大小分布均匀.La0.5Pr0.5CrO3在场冷条件下的磁化强度以及在7K时的磁滞回线的测量结果表明,在260K表现出顺磁到反铁磁转变,在200K时磁化率达到最大值,随后磁化率随着温度的降低而急剧减小,在大约94K的时候磁化率为0,随着温度的进一步降低,磁化率为负值.The La1-xPrxCrO3（x=0-0.6）nanocrystalline powders have been prepared by sol-gel method using citric acid as the fuel. The powder calcined at 600℃ exhibited a pure phase of perovskite, had a particle size of about 40 nm. The diamagnetism in La0.5 Pr0.5 CrO3 under field-cooled conditions and hysteresis in magnetization versus applied field M （H） isotherms at 7 K have been observed obviously. The compound shows a canted-antiferomagnetic transition at260 K and a small peak with appositive sign at 200 K. Below this temperature, M decreases with decreasing temperature, passes through a zero value （ M = 0） around 94 K.

关 键 词：溶胶凝胶法 La1-xPrxCrO3 纳米晶 类钙钛矿结构氧化物 

分 类 号：O482.5[理学—固体物理]