Published online by Cambridge University Press: 14 March 2018
During the course of a study of the interaction of certain pure refractory oxides at high temperatures it became necessary to obtain accurate values for the lattice parameters of α-alumina and chromic oxide. Values obtained by previous workers, listed in table I, did not attain a greater accuracy than one part in 2000, whereas the use of large-diameter powder cameras calibrated with quartz now yield lattice parameters accurate to at least one part in 30,000.
Samples of the calcined oxides were examined in a 19 cm. diameter powder camera, alumina with cobalt Kα radiation and chromic oxide with chromium Kα radiation. Results are given in tables II and III.