Elastic Constants of Nickel Oxide

Previous measurements of the single crystal elastic constants of NiO by ultrasonic techniques have been in wide disagreement. This paper gives the results of recent data obtained from several well characterized NiO single crystals. The present results for the antiferromagnetic phase at 298 K are different from the previous data and rectify certain questions about the elastic anisotropy ratio C44/C' and bulk modulus Ks.