氧含量对Pr1.85Ce0.15CuO4-x和Pr2CuO4-x结构、磁性和超导电性的影响

Effects of Oxygen Content on Structure, Magnetic Properties and Superconductivity of Pr1.85Ce0.15CuO4-x and Pr2CuO4-x System

摘要:

通过固相反应法制备了电子型Pr1.85Ce0.15CuO4-x和其母体Pr2CuO4-x。X射线衍射表明：制备的样品具有单相结构，杂相比较少。磁测量的结果表明：在Pr1.85Ce0.15CuO4-x中，0.05≤x≤0.20(质量分数，%, 下同)时具有超导电性，起始转变温度Tc=24.5 K。而Pr2CuO4-x仅仅通过调节氧含量不能实现超导。并且通过氧含量对Pr1.85Ce0.15CuO4-x和Pr2CuO4-x结构、磁性的不同影响的对比研究发现，在Pr1.85Ce0.15CuO4-x中通过调节氧含量实现超导的原因是引入自由载流子。Pr2CuO4-x不能实现超导的原因是氧空位出现在不同的氧位上, 并对相关机制进行了探讨

Abstract:

The samples of Pr1.85Ce0.15CuO4-x and Pr2CuO4-x were prepared by a solid reaction method. X-ray diffraction patterns reveal that single-phase Pr1.85Ce0.15CuO4-x and Pr2CuO4-x have been obtained with a small amount of impurity phases. For the samples of Pr1.85Ce0.15CuO4-x, superconductivity transitions are observed in the range of 0.05≤x≤0.20, and Tconset is 24.5 K. The samples of Pr2CuO4-x can not achieve superconductivity only by adjusting the oxygen content. By the comparison of different effects of the oxygen content on structure and magnetic properties, it is found that in Pr1.85Ce0.15CuO4-x samples the reason of superconductivity realization by adjusting oxygen content is free carrier introduction, while for Pr2CuO4-x the reason why the superconductivity does not realize is that oxygen vacancies do not appear in the same oxygen position. The relative mechanism was discussed