Crystalline R-zirconium phosphate, Zr(HPO 4 ) 2 ‚H 2 O, was obtained by direct precipitation of soluble salts of zirconium(IV) with phosphoric acid. The fresh compound transforms, by hydrolysis, into amorphous or semicrystalline hydroxophosphates with a P/Zr molar ratio of less than two. These facts contradict the formation mechanism of zirconium phosphates admitted by researchers for over more than 40 years. The materials are characterized by chemical, textural, and thermal analysis, powder X-ray diffraction, and scanning electron microscopy.

New crystalline phases of fibrous titanium(IV) oxophosphates were prepared hydrothermally from titanium(IV) chloride in phosphoric acid solutions. The influence of several factors (concentration of reagents, molar ratio P:Ti in the reaction mixture, and reaction times) was studied. A phase diagram of the system is given. On the basis of elemental and thermal analysis, X-ray powder diffraction, 31 P MAS NMR, and IR spectroscopy, the formula Ti 2 O-(PO 4 ) 2 ‚2H 2 O was assigned to the novel compounds. The new phases (π-TiP and F-TiP) have different structures. The crystal structure of F-TiP was solved from X-ray powder data and was shown to be of the framework type with tunnels parallel to the c-axis direction. The absence of n-alkylamine intercalation processes for both compounds and other physical and behavioral similarities suggests a framework type structure for π-TiP also. The ion-exchange behavior toward alkali and alkaline earth ions was studied.

Chemical nature of products, formed during electrochemical dissolution of polycrystalline 3C-SiC substrate in HF:ethanol mixture, was studied by means of FTIR spectroscopy, temperature-programmed desorption mass-spectrometry (TPD-MS), nanoparticles (NPs) with sizes of 1 -10 nm is described. CFO NPs easily dissolves in polar organic solvents (ethanol, CH 2 Cl 2 , etc); their solutions demonstrate intense yellowish-green photoluminescence under UV excitation. A model of the CFO chemical structure based on relatively small graphene domains interconnected with partially fluorinated hydrocarbon groups and terminated by carboxylic acid (-CO 2 H), ethyl ester (-CO 2 C 2 H 5 ), perfluorinated functional groups and polycarboxylated alkyl chains is proposed. Presence of carboxylates allows easy functionalization of the CFO NPs via amide chemistry. In particular, grafting of octadecyl groups makes CFO NPs soluble in hydrocarbons.

Nominally pure nanocrystalline KTaO 3 was thoroughly investigated by micro-Raman and magnetic resonance spectroscopic techniques. In all samples the defect driven ferroelectricity and magnetism are registered. Both ordering states are suggested to appear due to the iron atoms and oxygen vacancies. The concentration of defects was estimated to be 0.04 and 0.06-0.1 mole %, respectively. Note that undoped single crystals of KTaO 3 are nonmagnetic and have never exhibited ferromagnetic properties. The results enable us to refer a nanosized KTa(Fe)O 3 to the class of multiferroics and assume that it could perform the magnetoelectric effect at T<29 K. It was also established that the critical concentration of impurity defects necessary to provoke the appearance of the new phase states in the material strongly correlates with the size of the particle; as the size of the particle decreases, the critical concentration decreases as well.