Nd_(1.85)Ce_(0.15)CuO_(4±δ)单晶ab面与c方向电阻率的比较  

COMPARISONS OF IN-PLANE AND OUT-OF-PLANE RESISTIVITIES OF Nd_(1.85)Ce_(0.15)CuO_(4±δ) SINGLE CRYSTAL

作　　者：王建彬[1,2] 杨宏顺[2] 陈旭东[2] 刘剑[2] 孙成海[2] 高慧贤[2] 成路[2] 曹烈兆[1,2] 

机构地区：[1]中国科学技术大学结构分析开放实验室 [2]中国科学技术大学物理系,合肥230026

出　　处：《低温物理学报》2008年第4期283-287,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:10374082)资助项目~~

摘　　要：本文通过对Nd_(1.85)Ce_(0.15)CuO_(4±δ)单晶ab面(ρab)和c方向电阻率(ρc)的测量,发现未经过氮气退火的样品的ρc与温度成线性依赖关系,但是同一个样品经过氮气退火后的ρc中不仅有一次方的温度依赖关系还有二次方的.这说明样品经过氮气退火后,电子与空穴两种载流子共同参与导电.样品在退火处理前的各向异性比(ρc-ρc0)/(ρab-ρab0)存在强的温度依赖关系,这是由于ρc与温度成线性依赖关系,然而ρab不仅有一次方的温度依赖关系还有二次方的.样品经过退火处理后的各向异性比存在弱的温度依赖赖关系,这是由于ρc与ρab中都同时有一次方和二次方的温度依赖关系.我们用电子和空穴沿c方向有不同的隧穿几率来解释ρc和(ρc-ρc0)/(ρab-ρab0).Both in-plane （ρab） and out-of-plane resistivities （ρc） are investigated on Nd1.85Ce0.15CuO4±δ single crystal. The variation of ρc from linear T dependence in as-grown curve to the appearance of T2 component in 2 hours curve is observed, and the ρc decreases simultaneously. This behavior is the distinct evidence that two kinds of charge carriers coexist after annealing treatment. The ratio （ρc-ρco）/（ρab-ρabo ） of the as-grown curve shows a strong temperature dependence, due to the linear T dependence in ρc while the coexistence of T and T2 dependences in ρab. Contrarily, the ratios of annealed curves show the weak tem- perature dependence, attributed to the coexistence of T and T2 dependences in pc and Pab. We use the different tunneling rates of electrons and holes along the c axis to explain the behavior of ρc and the high （ ρc-ρco ） / （ ρab-ρabo ）.

关 键 词：电阻率 双载流子 隧穿几率 

分 类 号：O738[理学—晶体学]