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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).
In this paper, by measuring the ab plane (ρab) and c-direction resistivity (ρc) of single Nd_ (1.85) Ce_ (0.15) CuO_ (4 ± δ) single crystal, it is found that the ρc of the samples without nitrogen annealing is linearly dependent on the temperature , But there is not only a quadratic dependence of temperature on ρc in the same sample annealed by nitrogen, which indicates that after the sample is annealed by nitrogen, both carriers of electrons and holes participate in the conductance. There is a strong temperature dependence of the anisotropy ratio (ρc -ρc0) / (ρab-ρab0) before annealing, which is due to the fact that ρc is linearly dependent on temperature. However, ρab has not only a one-way temperature dependence but also two The anisotropy of the samples after annealing is weaker than the temperature dependency, because both ρc and ρab have a first-order and second-order temperature dependencies. We use the electron and hole edges There are different tunneling probabilities for c direction to explain ρc and (ρc-ρc0) / (ρab-ρab0).