Order-disorder phase transition in titanium carbohydrides

Titanium carbides exhibit an order-disorder phase transition associated with the starred wave vector k/sup →/ = [1/2, 1/2, 1/2]. Cubic titanium carbohydrides also undergo an order-disorder phase transition. The goal of this work is to study the concentration dependence of the transition temperature T/sub c/ and to determine the energy characteristics for interaction between interstitial atoms in the carbides and carbohydrides of titanium. The homogeneity and single-phase character of the samples was monitored by x-ray-phase and neutron-phase analyses. The incorporation of hydrogen in titanium carbide results in increase of the phase T/sub c/. The T/sub c/ characteristics as a function of carbon and hydrogen content are described qualitatively within confines of the average field theory. The concentration dependence of the deformation interaction potentials between interstitial atoms is considered