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The Li4xTi1-xP2O7(x = 0, 0.06, 0.1, 0.2) powders have been synthesized by the solid state reaction and their ceramics have been sintered. The Li4xTi1-xP2O7(x = 0.06, 0.1, 0.2) compounds have cubic superstructure 3×3×3 (space group Pa-3), which is also typical for TiP2O7pyrophosphate. The electrical properties of the ceramics were investigated in the frequency range of 10 to 3·109Hz and temperature interval of 400–720 K by impedance spectroscopy. The relaxation dispersion region in the conductivity and dielectric permittivitty spectra of Li4xTi1-xP2O7(x = 0, 0.06, 0.1, 0.2) ceramics was found. [ABSTRACT FROM AUTHOR]

LiFeP2O7and Li0.9Fe0.9Ti0.1P2O7were synthesised by solid-state reaction and ceramics were sintered. The structure of compounds was studied in the temperature range 300–700 K by X-ray diffraction. Ceramics’ surfaces were investigated by scanning electron microscope. Binding energies of Fe 2p, P 2p and O 1s core levels at ceramics’ surfaces have been determined by X-ray photoelectron spectroscopy and different valence states of Fe and P were detected. Elemental compositions of the compounds were studied by energy dispersive X-ray spectrometer. Impedance spectroscopy was performed in the frequency range 10 Hz–3 GHz and in the temperature interval 400–700 K. The changes of the activation energy of ionic conductivity at 528 and 550 K for LiFeP2O7and Li0.9Fe0.9Ti0.1P2O7, respectively, were found. The phenomena can be related to disordering in the unit cells of the compounds. [ABSTRACT FROM AUTHOR]

Abstract: The powders of Li1+y Ge2−x−y Ti x Al y (PO4)3 (x =0.1÷0.3, y =0.07÷0.21) have been synthesized by a solid phase reaction. The structure of the compounds was determined by X-ray diffraction patterns from the powder. The compounds belong to the rhombohedral symmetry (s. g. R3¯c) with six formula units in the lattice. The sintering of the Li1+y Ge2−x−y Ti x Al y (PO4)3 ceramics was conducted at temperature T =1363 K for 1 h in air. The ionic conductivity of the ceramics was investigated by impedance spectroscopy in the frequency range from 1 MHz to 1.2 GHz at temperatures from 300 K to 600 K. Two dispersions regions were found in ionic conductivity spectra for all the compounds. The dispersions are caused by the ion transport in grain boundaries and in grains of the ceramic samples. The substitution of Ge4+ →Ti4+, Al3+ leads to the changes in the structure parameters and electrical properties of the compounds. [Copyright &y& Elsevier]

Abstract: Li1.3AlyYx−yTi1.7(PO4)3 (x=0.3; y=0.1, 0.2) solid electrolyte compounds were synthesized by solid state reaction and studied by X-ray diffraction. At room temperature the compounds belong to a rhombohedral symmetry (space group Rc) with six formula units in the unit cell. Ti 2p, O 1s, P 2p, Li 1s, Y 3d, and Al 2p core level XP spectra at Li1.3AlyYx−yTi1.7(PO4)3 (x=0.3; y=0.1, 0.2) ceramic surfaces have been determined by XPS. The measurements of the electrical properties of the ceramic samples in the frequency range 10Hz–1MHz were carried out by a two probe method and a four probe method. The measurements in the microwave range (3·105–3·109 )Hz were performed in a coaxial line, the part of the inner conductor which was replaced by the sample. The investigation of the electrical properties of the ceramic samples was carried out in air in the temperature range (300 to 700)K. The increase of the stoichiometric factor y of the compounds leads to the increase in the total and bulk conductivities of ceramics and decreases their activation energies. [Copyright &y& Elsevier]

Abstract: The solid electrolyte Li2.8Sc1.8−y Y y Zr0.2(PO4)3 (where y =0, 0.1) compounds were synthesized by a solid state reaction and studied by X-ray diffraction. At room temperature the compounds belong to orthorhombic symmetry (space group Pbcn) with four formula units in the unit cell. Elemental compositions and binding energies of Zr 3d, Sc 2p, Y 3d, P 2p, O 1s, and Li 1s core level at Li2.8Sc1.8Zr0.2(PO4)3 and Li2.8Sc1.7Y0.1Zr0.2(PO4)3 ceramics’ surfaces have been determined by XPS. Impedance spectroscopy of the ceramics has been performed in the frequency range 10–3×109 Hz in the temperature interval 300–600K. The substitution of Sc by Zr and Y in the host compound Li3Sc2(PO4)3 leads to the increase of ionic conductivity of the new ceramics. [Copyright &y& Elsevier]