【摘要】 采用扩展X射线精细结构谱(EXAFS)分析了Mg65Cu25YxGd10-x(x=0,5,10)非晶合金局域原子结构及合金的玻璃形成能力差异的原因。结果表明,随着替代元素Gd含量的增加,淬态Mg65Cu25YxGd10-x非晶合金吸收原子Cu周围的配位数单调增加,而最近邻原子间距呈现出微弱的下降,短程有序进一步增强。Mg65Cu25YxGd10-x系非晶合金中Cu原子周围形成配位数越大、原子间束缚更加紧密的多面体构型的短程有序结构,越有利于合金玻璃形成能力的提高。更多还原

【Abstract】 Local atomic structures of amorphous Mg65Cu25YxGd10-x (x=0,5,10) alloys and the difference in glass-forming ability of them have been studied by extended X-ray absorption fine structure (EXAFS). Results showed that the coordination number around Cu atoms in amorphous Mg65Cu25YxGd10-x alloys increased monotonously while the distance between Cu atoms and their nearest neighbor atoms decreased slightly with the increase of element Gd content, indicating the short range order around the Cu atoms improved. The formation of polyhedral short-range order unit with more coordination number and stronger binding around Cu atoms in Mg65Cu25YxGd10-x alloys was in favor of the improvement of glass-forming ability.更多还原