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Mesoporous maghemite γ-Fe2O3 was obtained by thermal decomposition of iron citrate xerogel hydrate. The influence of precursor molar concentration and calcination temperature on the material phase composition, morphology, crystalline and magnetic microstructure, surface condition and optical properties was studied. The model of mesoporous γ-Fe2O3 formation is proposed. Obtained maghemite was tested as cathode material for lithium power sources. Increase of lithium power sources specific capacity and energy with the samples specific surface area enlarging is determined. Two kinetic processes are observed during discharge processes: lithium accumulation at the cathode material/electrolyte interface and diffusion of lithium ions into the material crystal structure. The diffusion coefficients of lithium in the cathode material on the different stages of discharge process are calculated.

Спільна науково-дослідна лабораторія фізики магнітних плівок Інституту металофізики ім. Г. В. Курдюмова НАН України та ДВНЗ Прикарпатський національний університет ім. Василя Стефаника, вул. Шевченка, 57, 76025 Івано-Франківськ, Україна Роботу присвячено встановленню умов одержання безводного фториду заліза методою термічного розкладу тригідрату трифториду заліза. Уточ-нено базис кристалічної структури -FeF 3 3H 2 O. Встановлено температур-ні границі розкладу фази -FeF 3 3H 2 O та продуктів її дегідратації. Одер-жано нанокристалічний трифторид заліза ромбоедричної модифікації.Работа посвящена установлению условий получения безводного фторида железа методом термического разложения тригидрата трифторида желе-за. Уточнён базис кристаллической структуры -FeF 3 3H 2 O. Установлены температурные пределы разложения фазы -FeF 3 3H 2 O и продуктов её де-гидратации. Получен нанокристаллический трифторид железа ромбоэд-рической модификации.The article deals with the conditions for anhydrous iron fluoride obtaining by thermal decomposition of iron trifluoride trihydrate. The basis of the -FeF 3 3H 2 O crystal structure is outlined. Temperature limits of the -FeF 3 3H 2 O phase decomposition as well as products of its dehydration are established. Nanocrystalline iron trifluoride of rhombic modification is obtained.Ключові слова: FeF 3 , кристалічна структура, термічний розклад, Мессба-уерівська спектроскопія, термогравіметричний аналіз. Металлофиз. новейшие технол. / Metallofiz. Noveishie Tekhnol. 2015, т. 37, № 3, сс. 355-365 Оттиски доступны непосредственно от издателя Фотокопирование разрешено только в соответствии с лицензией 2015 ИМФ (Институт металлофизики им. Г. В. Курдюмова НАН Украины) Напечатано в Украине.

The phenomenological model of sulphate anions effect on the nanodispersed titania synthesis during hydrolysis of titanium tetrachloride was studied. It was proposed that both chelating and bridging bidentate complexes formation between sulphate anions and octahedrally coordinated [Ti(OH)h(OH2)6−h](4−h)+ mononers is the determinative factor for anatase phase nucleation.

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Mesoporous maghemite (γ-Fe2O3), obtained by thermal decomposition of iron citrate xerogel hydrate, was investigated by X-ray diffraction, scanning electron microscopy, the Mössbauer and impedance spectroscopies and low temperature nitrogen adsorption. The influence of precursor molar concentration on the material morphology, crystalline and magnetic microstructures and electric conductivity was studied. Obtained results open up the possibility for synthesis of ultrafine γ-Fe2O3 with controlled structural and morphological characteristics.

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A method of synthesis of mesoporous γ-Fe 2 O 3 by thermal decomposition of iron citrate has been proposed. Investigations of the crystalline and magnetic structure of obtained materials were done. Nanodispersed maghemite (γ-Fe 2 O 3 ) with the sizes of coherent scattering regions of about 4 -7 nm consisted of one phase only after gel sintering at 200, 250 and 300°C. The particles of synthesized materials were both in magnetically ordered, and superparamagnetic states, and they formed a grid-like mesoporous structure. The influence of magnetic dipole interparticle interaction on the parameters of Mossbauer spectra was observed. A phenomenological model of the differences between nanodispersed γ-Fe 2 O 3 magnetic microstructures obtained after annealing at different temperatures was presented.