镓一镁二元相图研究

本文用两种差热分析方法即“一步法”和“二步法”以及多晶X-射线衍射法对镓-镁二元系相图进行了研究.修正了前人的工作. 为了考察该二元体系的金属间化合物是否以镓原子多面体簇状结构存在,作者对富镓部分相图(镓原子百分含量大于71.4％)进行了较为细致的研究.在三种不同比例下(含镓量分别为85at.％、90at.％、95at.％)合成,分离得到了颗粒状晶体.对这些晶体进行了差热分析和多晶X-射线研究.分析结果表明:从这三种不同比例的合金中分离得到的晶体为同一金属间化合物Mg_2Ga_5,也是该二元系镓含量最高的金属间化合物.考察Ga-Mg体系中存在的五种金属间化合物的结构,未能发现镓原子以多面体簇状结构存在的现象.

Study on the Phase Diagram of Mg-Ga Binary System

The phase diagram of Mg-Ga system was revised by using "one-step" and "two-step" differenlial thermal analysis methods and Powder X-ray diffraction. In the galliumrich part (>Ga71.4at.%) we obtained single crystal particulates (or particles) by separating alloys containing Ga85at. %, 90at.%, 95at.% respectively. The results of thermal analysis and powder X-ray diffraction of these crystals show that the particulates are the same compound Mg2Ga5. A survey of structures of the five compounds existing in Mg-Ga system was made and no gallium cluster structure in any of the five intermetallic compounds was found.