钴掺杂铁基超导单晶的超导体积分数测量

摘要

Centimeter-sized NaFe1-xCoxAs single crystal plates were grown using self-flux method.Non-linear M-H data showed that NaFe1-xCoxAs belongs to the second type of superconductors with a superconducting mixing zone.According to the Meissner effect of superconductor, the superconducting volume fraction in the lower critical field was 100％, the superconducting volume fractions of the series of Co-doped samples were calculated.Compared with NaFe1-xCoxAs superconducting phase diagram, it was shown that the larger the superconducting volume fraction, the higher the transition temperature of the superconductor, and the better the superconducting performance.%采用自助熔剂法生长了cm量级的NaFe1-xCoxAs系列高质量单晶.M-H测量结果表明NaFe1-xCoxAs属于第二类超导体, 存在超导混合区.根据超导体的Meissner效应, 超导样品处于下临界场范围内时超导体积分数为100％的特点, 计算出了系列掺杂样品的超导体积分数, 并与NaFe1-xCoxAs的相图进行了对比研究, 结果表明单晶样品超导体积分数越大, 其超导转变温度越高, 超导性能也越好.