Formation of Superconducting Phase by Laser Quenching

亚稳超导相可能是高T_c相，许多研究者试图用多种方法来获得亚稳超导相。激光淬火冷却速度快，是获得亚稳定相的一种很好的方法。本文介绍了激光淬火的方法，用激光淬火的方法研究了薄膜的超导性质：(A)用激光淬火的方法从非晶态的V-Si薄膜中获得了V_3Si相。T_COSET约为14K。(B)用激光退火法获得了亚稳相V-Al薄膜。(C)激光淬火没有得到亚稳的A15Nb_3Al相。激光淬火后，观察到了体心立方结构的Nb-Al相。(D)激光淬火后，得到了面心立方结构的亚稳定相Nb_3Si，但没有得到亚稳相A15Nb_3Si。

It hase been suggested that metastable superconducting phase would be a high-Tc phase and many investigators have been attemped to get a metastable superconducting phase by several methods. Laser quenching is a good method to get a meta stble phase,because cooling rate is very fast. In this report,we show the laser quenching method,the superconducting properties of films with laser aneealed.(a) V-Si filmA15 V_3Si phase was obtained from amorphous V-Si film by laser quenching. T_conset was about 14 K.(b) V-A1 filmA15 V_3Al,which is metastable phase, was obtained by laser annealing. T_c onset was about 12 K,which is highet value for A15 V_3Al phase now.(c) Nb-Al filmMeta stable A15 Nb_3Al phase was not obtained by laser quenching.After laser annealing,bcc Nb-Al phase was observed.(d) Nb-Si filmAfter laser quenching, fcc Nb_3Si of meta stable phase was obtained,but A 15 Nb_3Si phase was not obtainedIt was found that laser quenching is a good method to get a metastable phase