论氖型结构离子的化合物的折射率

无机晶体的折射率不仅取决于它的化学成分及内部构造,而且取决于离子的电子壳层结构。作者在研究氧离子最紧密堆积构造的矿物的折射率时,曾指出轻元素Be,Li,Al,Na,Mg(惰性气体结构类型的离子)起着同样的作用,具有d层价电子的过渡族元素Fe,Ti,Mn,Cr,Sc等有较大的折射率增量。

ON REFRACTIVE INDICES OF THE COMPOUNDS OF IONS WITH THE Ne-TYPE STRUCTURE

In this paper the author studied the relation between refractive indices and densities of the compounds of the ions with Ne-type structure. Three conclusions have been reached as follows: ,(1) The refractive indices of these compounds depend upon rather only their densities than their compositions and structures. The linear relation between the refractive index and density essentially due to that F-1, O-2, Si+4, A1+3, Na+, Mg+2, P+5, S+6, Cl+7 have the same electron shell structure 1s2 2s2 2p6, instead of the same mean atomic weight for these compounds as suggested by O. L. Anderson.(2) On the basis of the electronegativety difference of the ions and the ionic character of bonds, these compounds may be divided into three groups. The functional relations between the refracrive indices and densities for three groups are a) n = 1 + O.116d (for fluorides); b) n = 1 + 0.183d (for sulphates and prechlorates) c) n = 1 + 0.204d (for silicates and oxydes) respectively.(3) The specific refractivities of Na2O,Al2O3,MgO, SiO2, P2O5 have all to be around 0.204, therefore, the revisions for the K values given by E. S. Larson are urgently needed.