【摘要】 用X射线衍射照相、X射线衍射仪及透射电子显微镜分析了用液相淬火技术制备的La₃₀Al₂₀合金样品,结果表明样品是非晶态结构。差热分析（DTA）结果表明,非晶态样品的晶化温度T_cr为280℃左右,玻璃温度T_g为242℃左右。非晶态样品低温高压（流体静压法）试验结果表明:压力从0至4.77kbar,T_c从3.87K提高到4.18K。高压下,超导前的剩余电阻与常压下相比较有明显下降。非晶态样品经高温高压（25kbar,～160℃,40min）处理后,X射线衍射仪分析结果表明:发生了由非晶态→晶态的结构相变。相变产物由平衡相α-La和新的亚稳过渡相组成。其T_c从～3.9K提高到5.7K,该亚稳相结构与化学成分尚不清楚。本文并对所获得的实验结果进行了讨论。更多还原

【Abstract】 The rapidly quenched La80Al20 alloy is amorphous. At atmospheric pressure, its crystallization temperature and glass temperature are ~ 280℃ and ~ 242℃ respec-tivily, according to DTA measurements. The superconducting transition temperature Tc increases from 3.87 to 4.18K, in the hydrostatic pressure range of 1-4770 bars, while its residual resistance decreases significantly. After high pressure-high temperature treatment (25kbar, ~ 160℃, 40 min), amorphous→ crystalline transition of La80Al20 alloy occurs, as disclosed by X-ray diffraction method. The product consists of a-La phase and a new metastable phase, and its T, increases from 3.9 to 5.7 K. Some preliminary discussion on the experimental results are also presented.更多还原