Changes in Lattice Constant of Cr₂O₃ near the Curie Temperature

Abstract

IN 1951 a communication by me under this title was published in Nature ¹. It showed that as Cr₂O₃ was cooled through the antiferromagnetic transition region, the c-axis (hexagonal setting) contracted sharply, whereas the a axes decreased almost linearly. Recently, R. J. Davis and W. E. Armstrong (private communication), in a study of a system involving Cr₂O₃, found that, the lattice parameters at room temperature of their Cr₂O₃ sample did not agree with those given by me. They also suggested that the cause of the disagreement was my indexing the 42&2bar;, 664 rhombohedral reflexion pair as the 42&2bar;, 652 pair. Re-examination of the data and a few additional measurements have shown that this is indeed the case.