Electron microscopy study of ordering of potassium ions in cubic KSbO₃

Ordered and disordered states of potassium ions in (111) tunnels in the structure of cubic KSbO₃ have been studied by high-resolution electron microscopy. N-beam calculations for the images of both the ordered and disordered states reproduce well the observed images. The disordered state changes into the ordered state under electron irradiation during the observations. Electron diffraction from the specimens and optical diffraction from the images show diffuse spots due to small domains of the long-range-ordered state, but no other diffuse scattering due to short-range order has been observed.