NEUTRON-DIFFRACTION STUDIES ON THE TIME-DEPENDENCE OF THE OXYGEN ORDERING IN LA2NIO4.105

We present a single-crystal neutron-diffraction study of the time dependence of the interstitial oxygen ordering in La2NiO4.105. We have studied the kinetics of the growth of the intercalated Bmab phase at different temperatures below the phase transition temperature (290.5 K). The transformation appears to occur by homogeneous nucleation and growth. The time dependence of the transformed fraction follows a universal curve when the time variable is scaled appropriately. The transformation rate peaks near 265 K. The domain size measured after saturation decreases with decreasing quench temperature due to the increase in nucleation rate. © 1995 The American Physical Society.