Band Structure, Physical Properties, and Stability of TiO by the Augmented-Plane-Wave Virtual-Crystal Approximation

Abstract

The augmented-plane-wave virtual-crystal approximation is used to compute band structures and densities of states of the titanium monoxide system as a function of vacancy concentration and composition. TiO is a nonstoichiometric, cubic refractory compound with a 15% intrinsic vacancy concentration on both sublattices. The effective-mass approximation and an experimental value for the electron relaxation time are used to estimate several transport properties. The theoretical values are compared with experiment and used to examine the validity of our one-electron, muffin-tin-potential model of a nonstoichiometric compound. As it stands, this model does not treat the potential between the muffin-tin spheres accurately. It gives a physically valid description for most transport properties, but not for cohesion. Nonetheless, if the conduction-band edge does not vary appreciably with composition or total vacancy concentration, the average electronic energy is a minimum at the observed vacancy concentration.* Based on work submitted by J. M. Schoen in partial fulfillment of the requirements for Ph.D degree at Columbia University. fWork supported by the U. S. Atomic Energy Commission under Contract AT (30-1)3553.t Present address: Bell Telephone Laboratories,

Calculation of Electronic Structure and Diffusion Thermopower of Cu-Ni and Ag-Pd Alloys by the APW-VCA Method

“…As has been shown in [13], a quite satisfactory agreement with experiment in calculations of the resistivity, absolute thermoelectric power and Hall coefficient for TiO in the frame work of the APW-VCA has been obtained. However, as we know, for metalic solid solutions the APW-VCA method was not used.…”

“…Unfortunately, the APW-VCA is an non-self-consistent procedure. As it has been noted in [13], that the errors in the assumed average potential between the MT-spheres may lead to incorrect spacings between the energy bands, but that does not change significantly their shapes. That is why the transport properties, which are defined by the energy-band shape at the Fermi surface are rather well described by this method.…”

Preparation of inkjet-printed titanium monoxide as p-type absorber layer for photovoltaic purposes

“…Titanium monoxide (TiO), known for its applications in decorative and protective coatings [1], has outstanding properties, such as extreme hardness of up to 19.6 GPa in fcc crystal structure (the same structure with TiN) [2], high melting point, and chemical inertness [3]. These are derived from TiO, which belongs to a broad family of compounds with hard refractory metals consisting of nitride and carbide binary derivatives of IIIA, IVA, and VA transition metals [3,4].…”

Ближний порядок и нестехиометрия в монооксиде титана TiO-=SUB=-y-=/SUB=- по данным квантово-химических расчетов

“…Влияние структурных вакансий, а также их упо-рядочения на электронную структуру и стабильность моноксида титана стало темой множества теоретических работ [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Наиболее достоверные данные получены для фазы без структурных вакансий и фаз с идеаль-но упорядоченными сверхструктурами.…”

“…В неупорядо-ченной фазе вакансии располагаются по узлам подреше-ток без дальнего порядка и не нарушают симметрию ба-зисной кристаллической структуры. При упорядочении вакансии перераспределяются по узлам подрешеток, в структуре возникает дальний порядок, и ее симметрия понижается [4][5][6][7][8][9][10][11].Влияние структурных вакансий, а также их упо-рядочения на электронную структуру и стабильность моноксида титана стало темой множества теоретических работ [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Наиболее достоверные данные получены для фазы без структурных вакансий и фаз с идеаль-но упорядоченными сверхструктурами.…”