Stable Ti9O10 nanophase grown from nonstoichiometric titanium monoxide TiOy nanopowder

Abstract

A new stable Ti 9 O 10 nanophase (sp. gr. Immm) has been detected by X-ray diffraction (XRD) after high energy ball milling and long-term vacuum annealing of nanocrystalline powder of nonstoichiometric disordered and ordered titanium monoxide TiOy with B1 structure (sp. gr. Fm3m).With the help of XRD data, the unit cell of the Ti 9 O 10 nanophase as well as the distribution of atoms and structural vacancies in the titanium and oxygen sublattices of this phase have been established. The crystal structure of Ti 9 O 10 is derived from that of TiOy by (a) a migration of the vacancies to the specific crystallographic planes of B1 structure and (b) by orthorhombic distortions. The DFT calculations of the full energy of the coarse-crystalline phases TiOy and Ti 9 O 10 revealed that the bulk ordered phase Ti 9 O 10 is not preferable in comparison with the bulk disordered cubic phase TiOy with the same content of vacancies in the sublattices, so, it is the nanostate that causes the formation of Ti 9 O 10 .

Effect of Stoichiometry and Ordering on the Microstructure of Titanium Monoxide TiOy

“…gr. Immm ) is formed only during the transition from a crystalline phase to a nanostate. − This phase was first prepared during the annealing of nonstoichiometric TiO y nanocrystals and TiO y /HAP nanocomposites; the formation of the Ti 4.5 O 5 phase occurs during the annealing of the titanium oxide nanocrystals of superstoichiometric composition only. − …”

Influence of high energy milling on titanium oxide Ti3O5 crystal structure

“…The Ti-O system is attractive from both fundamental and applied points of view [1][2][3][4][5][6]. Well known due to its unique properties, titanium dioxide is the most studied material in wide areas of science and industry, ranging from memristors and capacitors to photocatalysts and photosorbents [7][8][9][10].…”

Epitaxial stabilization of an orthorhombic Mg-Ti-O superconductor

“…century [55], stable Ti 9 O 10 bulk with high-purity is difficult to be synthesized for the inevitable coexistence with other titanium oxides, e.g., Ti 3 O 5 and TiO 2 (anatase) [56,57]. Nevertheless, the structure and phase purity of the film can be further confirmed by the wide-range reciprocal space mappings (RSMs) [58].…”

“…The overlayer framework of Ti atoms on the (100) plane of Ti 9 O 10 are presented in the top part of Fig. 3(c), where two vacancy-free planes composed of Ti 4g and O 4h positions are alternate with one vacancy plane formed by Ti 2a and O 2c positions (filled with vacancies by 75% and 50%, respectively) [55][56][57]. The film and substrate regions are clearly recognizable in the HAADF-STEM image [Fig.…”