BADANIA METODĄ DYFRAKCJI PROMIENIOWANIA X ORAZ SPEKTROSKOPII EFEKTU MÖSSBAUERA AgFeO2 DOMIESZKOWANEGO JONAMI Co, Ni i Al WYTWARZANEGO METODĄ HYDROTERMALNĄ

Delafossite AgFeO2, AgFe0.9Al0.1O2, AgFe0.9Ni0.1O2, and AgFe0.9Co0.1O2 powders were synthesized by hydrothermal method. The structural analysis and hyperfine interactions investigations were performed by X-ray diffraction and the Mössbauer spectroscopy. It was found that the (Al, Ni, Co)-doped delafossite phases with traces of metallic silver can be obtained during hydrothermal synthesis. Investigations revealed that the type of the incorporated element has an impact on the structural properties of the obtained delafossites. However, doping of cobalt, nickel, and alumina ions to the AgFeO2 delafossite structure does not cause significant changes in the values of the hyperfine interactions parameters. The of the Mössbauer spectra confirm the paramagnetic character of the obtained compounds at room temperature.Proszkowe próbki delafosytów AgFeO2, AgFe0.9Al0.1O2, AgFe0.9Ni0.1O2, and AgFe0.9Co0.1O2 zostały wytworzone metodą hydrotermalną. Badania pozwalające na analizę strukturalną oraz oszacowanie parametrów oddziaływań nadsubtelnych przeprowadzono z wykorzystaniem dyfrakcji rentgenowskiej oraz spektroskopii efektu Mössbauera. Udowodniono, że za pomocą metody hydrotermalnej istnieje możliwość wytworzenia delafosytu AgFeO2 domieszkowanego jonami glinu, niklu i kobaltu z niewielką ilością zanieczyszczeń metalicznym srebrem. Badania wykazały, że rodzaj domieszki ma wpływ na właściwości strukturalne otrzymanych materiałów. Domieszkowanie jednak nie wpłynęło znacząco na zmiany wartości parametrów oddziaływań nadsubtelnych. Kształt zarejestrowanych widm mössbauerowskich  potwierdza paramagnetyzm otrzymanych materiałów w temperaturze pokojowej

Synthesis and characterization of AgFeO2 delafossite with non-stoichiometric silver concentration

The simple co-precipitation method was used to prepare AgxFeO2 delafossite with non-stoichiometric silver concentration in the range of x = 0.05-1. The obtained material was investigated using X-ray powder diffraction and 57Fe Mössbauer spectroscopy at room temperature. The structural and hyperfi ne interaction parameters were recognized in relation with decreasing silver concentration. The study revealed that the delafossite structure of AgxFeO2 was maintained up to x = 0.9; as the range of silver concentration was decreased to 0.05 ≤ x ≤ 0.8, a mixture of AgFeO2, Fe2O3 or/and FeOOH was formed

Characterization of Ti/SBA-15 Composites Synthesized by Chemical Vapour Deposition of Organic Titanium Compounds

The chemical vapour deposition technique was applied to obtain Ti/SBA-15 composites. Titanium(IV) tetraisopropoxide (TTIP) and titanium(IV) tetrabutoxide (TNBT) as sources of TiO2 were deposited on mesoporous silica (SBA-15) from the gaseous phase at 180–200 °C and treated at 250 °C in air. X-ray diffraction, Fourier-transform infrared spectroscopy, and Raman spectroscopy were used for structural investigations. Moreover, energy-dispersive X-ray spectroscopy studies and electrophoretic mobility measurements were conducted. Investigations revealed that Ti ions were mainly deposited on the SBA-15 surface as a thin layer of amorphous TiO2. However, Ti ions were not detected in the composites synthesized using TNBT as the starting reagent. The thickness of the deposited titanium oxide layer was estimated as 6–7 nm, and the porous silica structure has not been damaged. Moreover, the Ti ions deposition on the SBA-15 surface did not significantly change the investigated Ti/SBA-15 composites’ thermal stability compared to pristine silica