Physical properties and electronic structure of TaC-HfC solid solutions

Electronic structure of cubic HfxTa1–xCy carbides from X-ray spectroscopy studies and cluster self-consistent calculations

“…Due to the LMTO-ASA results by Nazarova et al [33], the main maximum of the band formed by the Ta 5d-like states hybridized with the C 2p-like states shifts monotonously towards the Fermi level when going from TaC to Ta 0.25 Hf 0.75 C through the ternary intermediate carbides, while the main maximum of the X-ray emission Ta N 3 spectra shifts towards smaller values of photon energies in the above sequence of compounds. Since Nazarova et al [33] have concentrated mainly on the changes of the energy distribution of the Ta 5d-like states in Hf x Ta 1-x C, in the present paper we aim at a comprehensive study of the energy distribution of electronic states of different symmetries of the constituent atoms of the Hf x Ta 1-x C system within the valence and conduction bands. Therefore, in the present paper we have made cluster self-consistent calculations of total DOS and partial densities of states of the constituent atoms of Hf x Ta 1-x C carbides.…”

“…In the very recent paper by Nazarova et al [33], total DOS and partial Ta 5d DOS were calculated using the linearized muffin-tin orbitals within atomic sphere approximation (LMTO-ASA) method as well as the X-ray emission Ta N 3 bands (Ta 5d, 6s → 4p 3/2 transition) were derived for a solid solution Hf x Ta 1-x C, where x = 0, 0.25, 0.5, and 0.75. Due to the LMTO-ASA results by Nazarova et al [33], the main maximum of the band formed by the Ta 5d-like states hybridized with the C 2p-like states shifts monotonously towards the Fermi level when going from TaC to Ta 0.25 Hf 0.75 C through the ternary intermediate carbides, while the main maximum of the X-ray emission Ta N 3 spectra shifts towards smaller values of photon energies in the above sequence of compounds. Since Nazarova et al [33] have concentrated mainly on the changes of the energy distribution of the Ta 5d-like states in Hf x Ta 1-x C, in the present paper we aim at a comprehensive study of the energy distribution of electronic states of different symmetries of the constituent atoms of the Hf x Ta 1-x C system within the valence and conduction bands.…”

Effect of nonstoichiometric TiN0.3 on diffusion behavior in TaC–TiN0.3 system

“…Understanding the diffusion behavior of carbides and nitrides of transition elements is critical because of their high melting point [8]. These compounds are difficult to densify due to their strong covalent bond and low self-diffusion coefficient.…”

Diffusion and solid solution formation between the binary carbides of TaC, HfC and ZrC

“…The characteristic of the carbides of Groups IV and V is their mutual solubility [5]. One of the reasons raising interest in investigating solid solution formation of tantalum, hafnium and zirconium carbides is their highest melting point among ever known refractory substances [6].…”