Neutron Diffraction Study of the Phase Transformations in Titanium Carbohydride TiC0.50Hy

Resumo

It is shown that the ordered phase of titanium carbohydride TiC_0.50H_0.31 with a face-centered cubic lattice (sp. gr. Fd\(\bar {3}\)m), obtained by self-propagating high-temperature synthesis, has an ordered antiphase domain structure with a period P = 16. This period is much larger than that in TiC_0.50H_y (y ≤ 0.22), with a lower hydrogen content (P ≈ 11). It is shown that TiC_0.50H_0.31 decomposes at temperatures T ≤ 900°C into the cubic phase of titanium carbide TiC_x (x ≥ 0.70) (sp. gr. Fm\(\bar {3}\)m) and the trigonal phase of titanium carbohydride Ti₂C_v′H_z′ (sp. gr. P\(\bar {3}\)m1).