X-Ray Study of Orientational Disorder in Cubic RbNO₃

Abstract

X-ray diffuse scattering due to the orientational disorder of NO 3 - ions is observed in cubic RbNO 3 of the CsCl type (phase III) with photographic and counter methods. The observed diffuse scattering is essentially identical to that observed previously in cubic NH 4 NO 3 by the present authors. The temperature dependence of its intensity suggests that the orientational disorder of NO 3 - ions does not show an anomaly associated with the dielectric anomaly in the vicinity of the transition to the higher temperature phase II, but shows the pre-transformation effect towards the lower temperature phase IV.