Separate determination of the amplitude of thermal vibrations and static atomic displacements in titanium carbide by neutron diffraction

Abstract

The amplitude of thermal (dynamic) atomic vibrations and meansquare static atomic displacements in titanium carbide TiC _x (x = 0.97, 0.88, 0.70) have been separately determined by measuring neutron diffraction patterns at two temperatures (T ₁ = 300 K and T ₂ = 80 K). The static lattice distortions in stoichiometric titanium carbide are experimentally found to be negligible. In the TiC _x homogeneity range, the amplitude $\sqrt {\overline {u_{dyn}^2 } }$ of thermal atomic vibrations significantly increases with a decrease in the carbon concentration. The Debye temperature has been determined for the first time in the TiC _x homogeneity range at both room and liquid-nitrogen temperatures.