名义成分为La_(1.0)Ca_(2.0)Mn_2O_7锰氧化物的压阻效应(英文)  

Pressure Effect on Electrical Properties of a Manganate with Nominal Composition La_(1.0)Ca_(2.0)Mn_2O_7

作　　者：朱嘉林[1] 刘振兴[1] 禹日成[1] 李凤英[1] 靳常青[1] 

机构地区：[1]中国科学院物理研究所极端条件实验室中国科学院凝聚态物理中心

出　　处：《高压物理学报》2006年第3期230-236,共7页Chinese Journal of High Pressure Physics

基　　金：NationalNaturalScienceFoundationofChina(102740995032110150332020);StateKeyDevel-opmentProgramforBasicResearchofChina(2002CB613301)

摘　　要：利用低温高压电阻原位测量装置（自箝铍青铜活塞-圆筒式压砧），在0～1．05GPa静水压力范围内，对以层状钙钛矿结构为主相、名义成分为La1.0 Ca2.0 Mn2O7 的锰氧化物样品进行了压阻效应研究。实验观测到异常的压阻效应。在低温5～150K范围内，压力为0．55GPa时，样品呈现出高达40％的压阻效应，而且，金属-绝缘体相变温度在低压范围内随压力的增加而增加，但随着压力的进一步增加而减小。Pressure effects on electrical properties of a manganate with nominal composition La1.0 Ca2.0 Mn2O7, which has a layered perovskite structure as majority phase,have been investigated under hydrostatic pressures up to 1.05 GPa by using a self-clamped CuBe piston-cylinder cell. An abnormal pressure effect was observed. At a pressure of 0.55 GPa,a large pressure resistance effect of ≈40% was observed in a lower temperature range of 5～150 K. Besides,it is found that the metal-insulator transition temperature increases at low pressure but deceases with further loading pressure.

关 键 词：层状钙钛矿结构锰氧化物 电阻率 压阻效应 

分 类 号：O521.2[理学—高压高温物理]