纳米Pr6O11粉末掺杂MgB2超导电性研究

本文采用固相反应法制备了一系列纳米Pr6O11掺杂的MgB2超导块材,掺杂量分别为0,1,3,5,10wt.%.X射线衍射结果表明:随着Pr6O11掺杂量的增加,MgB2的晶格常数也逐渐增大,也就是说Pr原子部分替代了MgB2晶格中的Mg原子.磁测量结果显示,Pr6O11的掺杂对MgB2的超导转变温度(Tc)有很小的抑制.在低含量Pr6O11掺杂(1wt.%)时,MgB2的临界电流密度(Jc)和不可逆场(Hirr)均有明显的提高,但进一步提高Pr6O11的掺杂量时,会损害MgB2在高场下的性能.文中同时也讨论了Pr6O11掺杂影响MgB2的Tc和Jc性能的机理.

SUPERCONDUCTING PROPERTIES OF NANO-Pr6O11 DOPED MgB2 BULK MATERIAL

Bulk samples of MgB_2 doped with 0, 1, 3, 5, 10wt. % Pr6O11 nano-powder were prepared using a solid-state reaction route. The lattice constants of Pr6O11-doped MgB_2 systematically increase with increasing doping level, indicating a substitution of Pr for Mg in the crystal structure, and consequently, superconducting transition temperature, Tc, of MgB_2 is slightly suppressed. At low doping level of 1 wt.% Pr6O11, the critical current density, Jc, and the irreversibility field, Hirr are improved. However, at higher doping levels, Pr6O11-doping seems harmful for the performance of MgB_2 in high magnetic fields. The Pr6O11-doping mechanism on Tc and Jc is also discussed.