Improvement irreversibility field by Ca substitution Nd123 single crystals
Kazuhisa Itoi, Takato Machi, Kiyoshi Kuroda, Hiromi Unoki, Naoki Koshizuka and Shigehiko Arai
Advances in Superconductivity XII (Proc. 12th. Int. Sym. Supercond.'99), Springer-Verlag
386