Structure of Some Crystals of Spinel Group

Abstract

The molecular structure of the crystals of spinel group was found to be a space-lattice having the same symmetry properties as the diamond-lattice. It consists of two hemihedral face-centred lattices interpenetrating each other, the elementary cube being made up of 8 molecules of R″R₂′′′O₄. The position of O atoms varies according to the nature of the atoms of R″ and R′′′. The theory is reconcilable with the results of Braggs' spectrometric experiments, except in the case of reflexion from (1, 1, 1) plane.
In conclusion, I wish to thank Professor Nagaoka for placing the resources of the Laboratory at my disposal and for his kind interest during the progress of the experiment. My thanks are also due to Professors S. Nakamura and T. Terada for their valuable criticisms.