方镁石固溶体的八面体结晶

A periclase solid solution in octahedral form

在用后的超高功率电炉炉底镁质耐火材料中发现了一种八面体结晶，它不是尖晶石，而是ＲＯ相。ＸＲＤ分析结果指出，该八面体的最强线的ｄ值虽与方镁石有些偏差，但其衍射面都符合于方镁石。其立方晶格常数ａ０为０．４２４９ｎｍ，要比方镁石大。籍ＥＤＡＸ测定了单晶的化学组成。用ＭＰＶ－３型显微光度仪测定了反射率，结果为Ｒ＿（５４６ｎｍ）＝１０．５６±０．３５％。文中讨论了人造方镁石的各种晶形和形成八面体结晶的条件。

A typical octahedral crystal was found in magnesia refractory used in bottom of UHP arc furnace.These crystals are not spinel,but RO phase.XRD data shows that the dvalues of the strongest line of the octahedral RO phase deviate from periclase in some degrees,however,all the diffraction planes are agreeable to periclase.The cubic lattice constant a0 is 0.4249nm,which is more than that of periclase.The chemical compositions of octahedral RO phase were analysed by EDAX,and the reflectance was measured with microphototmeter of MPV-3 type,the R_546nm is 10.56±0.35 %.Varied forms of crystals of artificial periclase and the conditions for growing into octahedral form are discussed in this paper.