Aim of investigation is to study the possibility of activating a promising Ni(OH) 2 , prepared using two-step high-temperature synthesis, by adding 3%, 5% and 10% (mol.) Al 3+ to Ni 2+ . For describing the intercalation of Al 3+ into hydroxide structure, "Separate-Solid-Liquid-Solid" mechanism, which included the formation of separate Al-containing phase on synthesis stage, and incorporation of Al 3+ into Ni(OH) 2 or formation of surface compounds during hydrolysis stage, has been proposed. EDX analysis of precursor confirmed the formation of separate Al-containing phases. By means of PXRD, EDX, SEM, TEM revealed realization of both ways of Al 3+ incorporation: at high amounts of Al 3+ (5% and 10% mol.), predominantly surface compounds are formed with distorted and altered particle shape and appearance of "core-shell" particles. At low amounts of Al 3+ (3% mol.), permeably doping occurs, with partial intercalation of Al 3+ into the nickel hydroxide structure. Based on CVA and GCDC results, Al 3+ acts as a poison upon the formation of surface compounds have been found. Upon doping of hot hydrolysis samples with aluminum, sample activation was observed, which resulted in an increase of specific capacity by 1.99 times, from 569 Fg −1 (pure Ni(OH) 2 ) to 1112 Fg −1 .

The samples of hydroxyapatite and carbonate substituted hydroxyapatite (CHA) were obtained under the influence of physical factors, namely ultrasound (US) and microwave (MW) radiations. The results of Fourier transform infrared spectroscopy and X-ray diffraction analysis have proved the formation of the calcium deficient hydroxyapatite and B-type CHA with the Ca/P ratio in the ranges 1.62-1.87. In vitro studies have showed the increased bioactivity of the samples, synthesized under the influence of physical factors as compared to the standard ones. The samples of both groups, synthesized under the influence of 600 W MW, have shown the greatest stability in biological environment. In vivo tests confirm that obtained under US and MW radiations hydroxyapatite-based biomaterials are biocompatible, non-toxic and exhibit osteoconductive properties. The usage of US and MW radiations can significantly shorten the time (up to 5-20 min) of obtaining of calcium deficient hydroxyapatite and B-type CHA in nanopowder form, close in structure and composition to the biological hydroxyapatite.

Crystallization of high temperature self-flux of system Na 2 O-K 2 O-TiO 2 -P 2 O 5 was investigated at different molar ratios (Na+K)/P = 0.9; 1.0 or 1.2 and Na/K = 1.0 or 2.0 over the temperature range 1000-650°C. The conditions of formation of complex phosphates K 0.10 Na 0.90 Ti 2 (PO 4 ) 3 (NASICONrelated) and K 0.877 Na 0.48 Ti ІІІ 0.357 Ti ІV 1.643 (PO 4 ) 3 (langbeiniterelated) have been established. The new obtained compounds were investigated using FTIR-spectroscopy, powder and single crystal X-ray diffraction and optical microscopy methods. The influence of alkaline metal nature on the structure formation of complex phosphates in the high temperature self-fluxes is discussed.

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