【摘要】 本文把非晶La₈₀Al₂₀在真空中、不同温度及时间条件下进行退火,以及在6GPa不同温度退火40min,并对退火样品的相结构及超导性进行了研究。发现真空中,250℃退火的样品晶化成了T>4.2K,不超导的单相四方La₄Al;300℃及450℃退火的样品晶化成La₃Al,α-La、β-La及一些未知杂相,这些多相混合物的T_c<6.0K。在6GPa 300℃及以下温度退火的样品,晶化成单相六角La₄Al,其晶格常数与六角La₃Al的完全相同,这些样品的T_c>5.1K;6GPa、350℃及以上温度退火的样品,晶化成La₃Al相及新未知相H,新相H的T_c为6.3K。更多还原

【Abstract】 In this paper, we studied the structures and superconductivity of the samples annealed from amorphous La80Al20 alloy under different treatments. It was found that when annealed in vacuum at 250℃, the amorphous alloy crystallized into the sampleof a tetragonal single phase La4Al for which there is no Tc as T>4. 2 K . When annealed in vacuum at 300℃, or 450℃, the amorphous samples crystallized into the samples of hexagonal La3Al, α-La, β-La and some unknown phases, the Tc of these multiphase samples is lower than 6.OK. When annealed under 6GPa, if annealing temperature Ta≤300℃, the amorphous alloy crystallized into the sample of hexagonal La4Al, the parameters of which are exactly the same as hexagonal La3Al and Tc of which is lower than 5.7K; if Ta≥350℃, the amorphous alloy crystallized into the sample of hexagonal La3Al and a unknown phase H, the Tc of new phase H is 6.3K.更多还原