钙钛矿结构材料Sr8CaRe3Cu4O24压力效应的研究

Properties of Sr_8CaRe_3Cu_4O_(24) with Perovskite Structure under Pressure

基于密度泛函理论,运用局域轨道密度近似+哈伯德相互作用和平均场方法,研究了新型钙钛矿结构材料Sr8CaRe3Cu4O24在不同压强下的机械、电磁性质,并探讨该材料的居里温度TC随压强变化的规律。计算结果表明:TC随着压强的增加而升高,费米面附近能隙逐渐减小。最后通过海森伯模型对此作出了较为合理的解释。

We have investigated the mechanism and electromagnetic properties of new compound Sr8CaRe3Cu4O24 under the hydrostatic pressure by the mean of local spin density approximation and mean field theory. Then we have discussed the internal mechanisms of the high magnetic transition temperature （Tc） and the regularity of Tc with the variety of hydrostatic pressure of this compound. Our calculation shows that the value of the magnetic transition temperature increases and the width of gap around Fermi level in DOS of this material descreases with the increasing of pressure. Our results show that a simple Heisenberg model and the theory of orbital order is suitable for this compound.