首页 | 本学科首页   官方微博 | 高级检索  
     

(1-x)La_(0.67)Ca_(0.33)MnO_3/xCuO复合体系与La_(0.67)Ca_(0.33)Mn_(1-x)Cu_xO_3电输运行为比较
引用本文:缪菊红,袁松柳,尹诗岩. (1-x)La_(0.67)Ca_(0.33)MnO_3/xCuO复合体系与La_(0.67)Ca_(0.33)Mn_(1-x)Cu_xO_3电输运行为比较[J]. 中国稀土学报, 2009, 27(6)
作者姓名:缪菊红  袁松柳  尹诗岩
作者单位:1. 南京信息工程大学数理学院,江苏,南京,210044
2. 华中科技大学物理学院,湖北,武汉,430074
基金项目:国家自然科学基金,江苏省高校自然科学基金,南京信息工程大学校科研基金 
摘    要:用不同实验方法制备了名义组分为(1-x)La_(0.67)Ca_(0.33)MnO_3/xCuO(LCMO/CuO)和La_(0.67)Ca_(0.33)Mn_(1-x)Cu_xO_3(LCMCO)两组样品,在宽的温度范围内研究了样品的电输运行为随Cu含量x的变化关系,发现这两组样品表现出不同的行为.对于LCMCO,随x的增加,金属-绝缘体转变温度T_p迅速降低,当x=5.5%,样品表现出绝缘体导电行为;而LCMO/CuO复合样品,当x≤6%时,随x增加,Tp逐渐下降,x≥6%时,T_p不再继续降低,所有样品几乎表现出相同的电输运行为.另外,这两组样品均表现出较好的低场磁电阻效应(LFMR),在0.3 T下样品的最大磁电阻分别达到了~76%和88%.基于样品结构以及制备过程的分析,我们认为LFMR效应的增强主要是因为颗粒边界上形成的Cu相关自旋无序层引起的.

关 键 词:钙钛矿锰氧化物  磁电阻  自旋无序  稀土

Comparative Study of Electrical Transport of (1-x)La_(0.67)Ca_(0.33)MnO_3/xCuO and La_(0.67)Ca_(0.33)Mn_(1-x)Cu_xO_3
Miao Juhong,Yuan Songliu,Yin Shiyan. Comparative Study of Electrical Transport of (1-x)La_(0.67)Ca_(0.33)MnO_3/xCuO and La_(0.67)Ca_(0.33)Mn_(1-x)Cu_xO_3[J]. Journal of the Chinese Society of Rare Earths, 2009, 27(6)
Authors:Miao Juhong  Yuan Songliu  Yin Shiyan
Abstract:The samples with nominal composition of (1-x) (1-x)La_(0.67)Ca_(0.33)MnO_3/xCuO (LCMO/CuO) and La_(0.67)Ca_(0.33)Mn_(1-x)Cu_xO_3 (LCMCO) were fabricated using different methods. The Cu content level (x) de-pendence on electrical transport behavior was investi-gated under a wide temperature range. It was found that the two series of samples had different behavior. For LCMCO, the metal-insulator transition tempera-ture (T_p) decreased sharply with increment of x and exhibited insulator behavior when x = 5.5%. While for LCMO/CuO composites, Tp shifted towards low temperature with the increase of x when x ≤6%, and the samples exhibited similar electrical transport be-havior when x≥6%. Furthermore, the low-field mag-netoresistance (LFMR) was enhanced in both sam-pies. The MR_0 values at a magnetic field of 0.3 T for the two samples could reach ~76% and ~ 88%, re-spectively. Based on the analysis of microstructure and sample preparation process, it was discussed that the enhancement of LFMR was attributed to the formation of Cu dependent materials with local spin disorder at grain boundaries.
Keywords:perovskite manganites  magnetoresistance  spin disorder  rare earths
本文献已被 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号