L. Lyashenko - Academia.edu (original) (raw)

Papers by L. Lyashenko

Research paper thumbnail of Interaction of Sc/sub 2/O/sub 3/ and TiO/sub 2/ at high temperatures

X-ray spectra were obtained for solid solution of Sc/sub 2/O/sub 3/ and TiO/sub 2/ in the tempera... more X-ray spectra were obtained for solid solution of Sc/sub 2/O/sub 3/ and TiO/sub 2/ in the temperature range 1100--1750degreeC. The solubility of each material in the other was determined, and diagrams of the crystal-phase transformations were produced.(AIP)

Research paper thumbnail of Ba2-xDyxCuO3+δ(0.20 ≤ x ≤ 0.25 and 0.30 ≤ x ≤ 0.37) solid solutions

Inorganic Materials, 1996

Research paper thumbnail of Synchrotron X-ray diffraction study of nanostructured Er2O3-TiO2 (50–60 mol % Er2O3) solid solutions

Inorganic Materials, 2013

Research paper thumbnail of Defect structure of xY2O3 · (1 − x)TiO2 (x = 0.5–0.58) solid solutions

Inorganic Materials, 2014

Research paper thumbnail of Defect structure of xSc2O3 · (1 − x)TiO2 (x = 0.4–0.5) solid solutions

Inorganic Materials, 2015

ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated ... more ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated that xSc2O3 • (1-x)TiO2 (x = 0.4-0.5) solid solutions consist of a fluorite-like (Fm3m) disorder phase and a nanoscale (10-50 nm) pyrochlore-like (Fd3m) ordered phase of the same composition, coherent with the disorder phase. We have determined their lattice parameters. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalysts supports, gas sensors, etc.

Research paper thumbnail of L. P. Lyashenko, L. G. Shcherbakova, E. S. Kulik, R. D. Svetogorov, and Ya. V. Zubavichus. Defect Structure of хSc2O3•(1−х)TiO2 (х=0.4−0.58) Solid Solutions // Inorganic Materials. 2015. V. 51. № 2. PP. 158−162 DOI:10.1134/S0020168515020120

X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xS... more X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xSc 2 O 3 ⋅ (1 -x)TiO 2 (x = 0.4-0.5) solid solutions consist of a fluorite like (Fm3m) disordered phase and a nanoscale ( 10-50 nm) pyrochlore like (Fd3m) ordered phase of the same composition, coherent with the disordered phase. We have determined their lattice parameters. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalyst supports, gas sensors, etc.

Research paper thumbnail of L.P. Lyashenko, L.G Shcherbakova, D.A. Belov, and A.V. Knotko. Electrical Conductivity of Nanostructured Fluorite-Like Sc4Ti3O12 // Inorganic Materials. 2009. V. 45. № 5. PP. 543-549 .

Inorganic Materials, 2009

ABSTRACT Single-crystal and polycrystalline samples of Sc4Ti3O12 have been shown to contain nanod... more ABSTRACT Single-crystal and polycrystalline samples of Sc4Ti3O12 have been shown to contain nanodomains (10–50 nm) with different degrees of ordering, coherent with the fluorite-like matrix. The oxygen-ion conductivity of this compound has been determined in the range 300–1000°C in air using impedance spectroscopy. The nanostructured single-crystal and polycrystalline samples are close in the activation energy for bulk conduction at both low and high temperatures: ≃1.26 and 1.29 eV in the range 300–775°C, ≃1.98 and 2.07 eV in the range 775–1000°C.

Research paper thumbnail of A.G. Afonin, L.A. Alekseeva, S.P. Borodai, L.P. Lyashenko, Phase Compositionof Lithium Aluminosilicate Glass-Ceramics. // Inorganic Materials, 2006, Vol. 42, No. 5, pp. 562–566

Research paper thumbnail of Synchrotron X-ray diffraction study of nanostructured Er2O3-TiO2 (50–60 mol % Er2O3) solid solutions

Inorganic Materials, 2013

Monochromatic synchrotron X ray diffraction data demonstrate that single crystal and polycrys tal... more Monochromatic synchrotron X ray diffraction data demonstrate that single crystal and polycrys talline xEr 2 O 3 ⋅ (1 -x)TiO 2 (x = 0.5-0.6) solid solutions consist of a fluorite like disordered (Fm3m) phase and a nanoscale ( 40-1000 nm) pyrochlore like ordered phase (Fd3m) of the same composition in the range 0.5 ≤ x ≤ 0.57, coherent with the disordered phase. Reducing the density of structural defects in the unit cell of Er 3 TiO 6.5 (x = 0.6) leads to a structural transformation of the pyrochlore like phase into a Ta 2 O 3 type ordered phase (Ia3), derived from the fluorite phase. In the composition range of the solid solutions (0.5 < x < 0.6), the lattice parameter of the fluorite like phase follows Vegard's law. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells.

Research paper thumbnail of Defect structure of xSc2O3 · (1 − x)TiO2 (x = 0.4–0.5) solid solutions

Inorganic Materials, 2015

ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated ... more ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated that xSc2O3 • (1-x)TiO2 (x = 0.4-0.5) solid solutions consist of a fluorite-like (Fm3m) disorder phase and a nanoscale (10-50 nm) pyrochlore-like (Fd3m) ordered phase of the same composition, coherent with the disorder phase. We have determined their lattice parameters. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalysts supports, gas sensors, etc.

Research paper thumbnail of A.G. Afonin, L.A. Alekseeva, S.P. Boroday, L.P. Lyashenko, L.G. Shcherbakova, E.I. Suzdaltsev. Phase composition of lithium aluminosilicate glass-ceramics // Inorg. Mater. 2006. V. 42. N 5. P. 623-627.

Inorganic Materials, 2006

ABSTRACT The phase composition of glass-ceramics produced by heat-treating lithium aluminosilicat... more ABSTRACT The phase composition of glass-ceramics produced by heat-treating lithium aluminosilicate glass at temperatures from 600 to 1300C has been determined by x-ray diffraction and electron probe x-ray microanalysis. The materials heat-treated in the range 1000–1230C have been shown to contain an Si0.65Al0.19Ti0.09Sb0.013Na0.032K0.013Ce0.008As0.013O1.864 glass phase and crystalline solid solutions: tetragonal spodumene-like Li1 − 4x − 2y TixZnyAlSi3O8 (x, y ≤ 0.05), sillimanite-based Al1.92Ti0.08SiO5.04, and rutile-based Ti0.99Sb0.01O2.005. The structures and lattice parameters of the crystalline phases have been determined.

Research paper thumbnail of Mechanism of structure formation in samarium and holmium titanates prepared from mechanically activated oxides

ABSTRACT We have studied the formation mechanism and phase transitions of samarium and holmium ti... more ABSTRACT We have studied the formation mechanism and phase transitions of samarium and holmium titanates prepared from mechanically activated oxide mixtures with the overall compositions Sm2(Ho2)Ti2O7 and Sm2TiO5. Mechanical activation of oxide mixtures leads to the formation of amorphous solid phases which crystallize in a distorted pyrochlore-like structure and contain OH groups on the oxygen site and structural vacancies up to 1000°C. In the range 800–1000°C, Sm2−x Ti1−y O5−δ (OH) n (x &lt; 0.02; y &lt; 0.08; δ, n &lt; 0.19) converts to a distorted orthorhombic phase as a result of the relaxation of internal stress and removal of OH groups. Above 1000°C, the phases studied have the compositions Sm2(Ho2)Ti2O7 and Sm2TiO5 and ordered pyrochlore-like and orthorhombic structures, respectively. The lattice parameters of the titanates have been measured in the range 800–1350°C. The internal stress produced by mechanical activation in the phases studied here fully relaxes by ∼1300°C.

Research paper thumbnail of . L. P. Lyashenko, L. G Shcherbakova. X-Ray Diffraction Data for Fluorite-Like Gd2ZrO5 and Gd2HfO5) // Inorganic Materials. 2012. V. 48. № 1. PP. 54-56.

Inorganic Materials, 2011

This paper presents X ray powder diffraction data for the Gd 2 MO 5 (M = Zr, Hf) compounds pre pa... more This paper presents X ray powder diffraction data for the Gd 2 MO 5 (M = Zr, Hf) compounds pre pared through coprecipitation followed by heat treatment at 1600°C: structure type, interplanar spacings, Miller indices, unit cell parameters, and X ray densities. The materials studied are shown to contain nano structured grains ranging in nanodomain size from Ӎ40 to 500 nm.

Research paper thumbnail of L.P. Lyashenko, D.A. Belov, L.G Shcherbakova. Conductivity of Sm2Ti2O7 и Sm2TiO5 // Inorganic Materials. 2008. V. 44. № 12. PP. 1349-1353.

Inorganic Materials, 2008

The oxygen-ion conductivity of porous materials, the coarse-grained pyrochlore-like Sm 2 Ti 2 O 7... more The oxygen-ion conductivity of porous materials, the coarse-grained pyrochlore-like Sm 2 Ti 2 O 7 and fine-grained Sm 2 TiO 5 compounds, produced by mechanical activation of initial oxides is studied at 400-1000 ° C. The Sm 2 TiO 5 samples contain ~15 wt % of the nanosized pyrochlore-like Sm 2 TiO 5 phase in addition to the rhombic phase. As determined by impedance spectroscopy, the ionic conductivities of Sm 2 TiO 5 and Sm 2 Ti 2 O 7 at 1000° C are 1.3 × 10 -3 and 1.8 × 10 -4 S cm -1 , and the activation energies of the bulk and grainboundary conductivities of the materials are 1.04 and 1.24 eV for Sm 2 TiO 5 and 1.69 and 1.80 eV for Sm 2 Ti 2 O 7 .

Research paper thumbnail of L. P. Lyashenko, L. G Shcherbakova, D. A. Belov, E. I. Knerel’man, and N. N. Dremova. Synthesis and Electrical Properties of Gd2MO5 (M = Zr, Hf) // Inorganic Materials. 2010. V. 46. № 12. PP. 1341-1347

Inorganic Materials, 2010

ABSTRACT Polycrystalline Gd2ZrO and Gd2HfO5 have been prepared by heat-treating coprecipitated ox... more ABSTRACT Polycrystalline Gd2ZrO and Gd2HfO5 have been prepared by heat-treating coprecipitated oxide mixtures, and their order-disorder phase transitions have been studied in the range 20–1600°C. The materials have been shown to consist of nanostructured grains with a nanodomain size of ∼40 nm. Their electrical conductivity has been determined by impedance spectroscopy in air between 300 and 1000°C. The 1000°C conductivities of Gd2ZrO5 and Gd2HfO5 are 3.7 × 10−3 and 1.8 × 10−3 S/cm, and the respective effective activation energies are 1.37 and 1.56 eV.

Research paper thumbnail of Study of solid solutions in the TiO2?Sc2O3 system by the method of x-ray photoelectron spectroscopy

Journal of Structural Chemistry, 1980

Research paper thumbnail of Mechanism of formation of barium cuprate-based solid solutions with perovskite-like structure doped with cadmium and yttrium oxides

Crystallography Reports, 2002

The influence of Y 2 O 3 and CdO content on the phase composition, structure, and electrical prop... more The influence of Y 2 O 3 and CdO content on the phase composition, structure, and electrical properties of Y 2 O 3 -CdO-BaO-CuO ceramics was studied. The concentration limits of the existence of the orthorhombic perovskite-like Y x Ba 2x Cd y Cu 1y O 3 + δ solid solutions (where 0.20 ≤ x ≤ 0.37 and y ≤ 0.2) and their unitcell parameters are determined.

Research paper thumbnail of Effect of a Nonequilibrium State on Phase Relations in the System TiO 2 –Sc 2 O 3 (40–50 mol % Sc 2 O 3 )

Inorganic Materials, 2004

The phase transitions in TiO2–Sc2O3 (40–50 mol % Sc2O3) samples prepared from coprecipitated and ... more The phase transitions in TiO2–Sc2O3 (40–50 mol % Sc2O3) samples prepared from coprecipitated and mechanically activated oxide mixtures are studied. It is shown that heat treatment below 1000°C leads to the formation of nonstoichiometric, metastable cubic phases with a distorted fluorite structure. With increasing temperature, this structure transforms into a stable fluorite-like structure through (low-symmetry) orthorhombic and hexagonal phases, which

Research paper thumbnail of Defect structure of xY2O3 · (1 − x)TiO2 (x = 0.5–0.58) solid solutions

Inorganic Materials, 2014

X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xY... more X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xY 2 O 3 ⋅ (1 -x)TiO 2 (x = 0.5-0.58) solid solutions consist of a fluorite like (Fm3m) disordered phase and a nanoscale ( 40-1000 nm) pyrochlore like (Fd3m) ordered phase of the same composition, coherent with the disordered phase. In the composition range of the solid solutions (0.5 ≤ x ≤ 0.58), the lattice parameter of the fluorite like phase follows Vegard's law. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalyst sup ports, gas sensors, etc.

Research paper thumbnail of Interaction of Sc/sub 2/O/sub 3/ and TiO/sub 2/ at high temperatures

X-ray spectra were obtained for solid solution of Sc/sub 2/O/sub 3/ and TiO/sub 2/ in the tempera... more X-ray spectra were obtained for solid solution of Sc/sub 2/O/sub 3/ and TiO/sub 2/ in the temperature range 1100--1750degreeC. The solubility of each material in the other was determined, and diagrams of the crystal-phase transformations were produced.(AIP)

Research paper thumbnail of Ba2-xDyxCuO3+δ(0.20 ≤ x ≤ 0.25 and 0.30 ≤ x ≤ 0.37) solid solutions

Inorganic Materials, 1996

Research paper thumbnail of Synchrotron X-ray diffraction study of nanostructured Er2O3-TiO2 (50–60 mol % Er2O3) solid solutions

Inorganic Materials, 2013

Research paper thumbnail of Defect structure of xY2O3 · (1 − x)TiO2 (x = 0.5–0.58) solid solutions

Inorganic Materials, 2014

Research paper thumbnail of Defect structure of xSc2O3 · (1 − x)TiO2 (x = 0.4–0.5) solid solutions

Inorganic Materials, 2015

ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated ... more ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated that xSc2O3 • (1-x)TiO2 (x = 0.4-0.5) solid solutions consist of a fluorite-like (Fm3m) disorder phase and a nanoscale (10-50 nm) pyrochlore-like (Fd3m) ordered phase of the same composition, coherent with the disorder phase. We have determined their lattice parameters. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalysts supports, gas sensors, etc.

Research paper thumbnail of L. P. Lyashenko, L. G. Shcherbakova, E. S. Kulik, R. D. Svetogorov, and Ya. V. Zubavichus. Defect Structure of хSc2O3•(1−х)TiO2 (х=0.4−0.58) Solid Solutions // Inorganic Materials. 2015. V. 51. № 2. PP. 158−162 DOI:10.1134/S0020168515020120

X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xS... more X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xSc 2 O 3 ⋅ (1 -x)TiO 2 (x = 0.4-0.5) solid solutions consist of a fluorite like (Fm3m) disordered phase and a nanoscale ( 10-50 nm) pyrochlore like (Fd3m) ordered phase of the same composition, coherent with the disordered phase. We have determined their lattice parameters. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalyst supports, gas sensors, etc.

Research paper thumbnail of L.P. Lyashenko, L.G Shcherbakova, D.A. Belov, and A.V. Knotko. Electrical Conductivity of Nanostructured Fluorite-Like Sc4Ti3O12 // Inorganic Materials. 2009. V. 45. № 5. PP. 543-549 .

Inorganic Materials, 2009

ABSTRACT Single-crystal and polycrystalline samples of Sc4Ti3O12 have been shown to contain nanod... more ABSTRACT Single-crystal and polycrystalline samples of Sc4Ti3O12 have been shown to contain nanodomains (10–50 nm) with different degrees of ordering, coherent with the fluorite-like matrix. The oxygen-ion conductivity of this compound has been determined in the range 300–1000°C in air using impedance spectroscopy. The nanostructured single-crystal and polycrystalline samples are close in the activation energy for bulk conduction at both low and high temperatures: ≃1.26 and 1.29 eV in the range 300–775°C, ≃1.98 and 2.07 eV in the range 775–1000°C.

Research paper thumbnail of A.G. Afonin, L.A. Alekseeva, S.P. Borodai, L.P. Lyashenko, Phase Compositionof Lithium Aluminosilicate Glass-Ceramics. // Inorganic Materials, 2006, Vol. 42, No. 5, pp. 562–566

Research paper thumbnail of Synchrotron X-ray diffraction study of nanostructured Er2O3-TiO2 (50–60 mol % Er2O3) solid solutions

Inorganic Materials, 2013

Monochromatic synchrotron X ray diffraction data demonstrate that single crystal and polycrys tal... more Monochromatic synchrotron X ray diffraction data demonstrate that single crystal and polycrys talline xEr 2 O 3 ⋅ (1 -x)TiO 2 (x = 0.5-0.6) solid solutions consist of a fluorite like disordered (Fm3m) phase and a nanoscale ( 40-1000 nm) pyrochlore like ordered phase (Fd3m) of the same composition in the range 0.5 ≤ x ≤ 0.57, coherent with the disordered phase. Reducing the density of structural defects in the unit cell of Er 3 TiO 6.5 (x = 0.6) leads to a structural transformation of the pyrochlore like phase into a Ta 2 O 3 type ordered phase (Ia3), derived from the fluorite phase. In the composition range of the solid solutions (0.5 < x < 0.6), the lattice parameter of the fluorite like phase follows Vegard's law. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells.

Research paper thumbnail of Defect structure of xSc2O3 · (1 − x)TiO2 (x = 0.4–0.5) solid solutions

Inorganic Materials, 2015

ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated ... more ABSTRACT X-ray diffraction charaterization with monochromatic synchrotron X-ray has demonstrated that xSc2O3 • (1-x)TiO2 (x = 0.4-0.5) solid solutions consist of a fluorite-like (Fm3m) disorder phase and a nanoscale (10-50 nm) pyrochlore-like (Fd3m) ordered phase of the same composition, coherent with the disorder phase. We have determined their lattice parameters. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalysts supports, gas sensors, etc.

Research paper thumbnail of A.G. Afonin, L.A. Alekseeva, S.P. Boroday, L.P. Lyashenko, L.G. Shcherbakova, E.I. Suzdaltsev. Phase composition of lithium aluminosilicate glass-ceramics // Inorg. Mater. 2006. V. 42. N 5. P. 623-627.

Inorganic Materials, 2006

ABSTRACT The phase composition of glass-ceramics produced by heat-treating lithium aluminosilicat... more ABSTRACT The phase composition of glass-ceramics produced by heat-treating lithium aluminosilicate glass at temperatures from 600 to 1300C has been determined by x-ray diffraction and electron probe x-ray microanalysis. The materials heat-treated in the range 1000–1230C have been shown to contain an Si0.65Al0.19Ti0.09Sb0.013Na0.032K0.013Ce0.008As0.013O1.864 glass phase and crystalline solid solutions: tetragonal spodumene-like Li1 − 4x − 2y TixZnyAlSi3O8 (x, y ≤ 0.05), sillimanite-based Al1.92Ti0.08SiO5.04, and rutile-based Ti0.99Sb0.01O2.005. The structures and lattice parameters of the crystalline phases have been determined.

Research paper thumbnail of Mechanism of structure formation in samarium and holmium titanates prepared from mechanically activated oxides

ABSTRACT We have studied the formation mechanism and phase transitions of samarium and holmium ti... more ABSTRACT We have studied the formation mechanism and phase transitions of samarium and holmium titanates prepared from mechanically activated oxide mixtures with the overall compositions Sm2(Ho2)Ti2O7 and Sm2TiO5. Mechanical activation of oxide mixtures leads to the formation of amorphous solid phases which crystallize in a distorted pyrochlore-like structure and contain OH groups on the oxygen site and structural vacancies up to 1000°C. In the range 800–1000°C, Sm2−x Ti1−y O5−δ (OH) n (x &lt; 0.02; y &lt; 0.08; δ, n &lt; 0.19) converts to a distorted orthorhombic phase as a result of the relaxation of internal stress and removal of OH groups. Above 1000°C, the phases studied have the compositions Sm2(Ho2)Ti2O7 and Sm2TiO5 and ordered pyrochlore-like and orthorhombic structures, respectively. The lattice parameters of the titanates have been measured in the range 800–1350°C. The internal stress produced by mechanical activation in the phases studied here fully relaxes by ∼1300°C.

Research paper thumbnail of . L. P. Lyashenko, L. G Shcherbakova. X-Ray Diffraction Data for Fluorite-Like Gd2ZrO5 and Gd2HfO5) // Inorganic Materials. 2012. V. 48. № 1. PP. 54-56.

Inorganic Materials, 2011

This paper presents X ray powder diffraction data for the Gd 2 MO 5 (M = Zr, Hf) compounds pre pa... more This paper presents X ray powder diffraction data for the Gd 2 MO 5 (M = Zr, Hf) compounds pre pared through coprecipitation followed by heat treatment at 1600°C: structure type, interplanar spacings, Miller indices, unit cell parameters, and X ray densities. The materials studied are shown to contain nano structured grains ranging in nanodomain size from Ӎ40 to 500 nm.

Research paper thumbnail of L.P. Lyashenko, D.A. Belov, L.G Shcherbakova. Conductivity of Sm2Ti2O7 и Sm2TiO5 // Inorganic Materials. 2008. V. 44. № 12. PP. 1349-1353.

Inorganic Materials, 2008

The oxygen-ion conductivity of porous materials, the coarse-grained pyrochlore-like Sm 2 Ti 2 O 7... more The oxygen-ion conductivity of porous materials, the coarse-grained pyrochlore-like Sm 2 Ti 2 O 7 and fine-grained Sm 2 TiO 5 compounds, produced by mechanical activation of initial oxides is studied at 400-1000 ° C. The Sm 2 TiO 5 samples contain ~15 wt % of the nanosized pyrochlore-like Sm 2 TiO 5 phase in addition to the rhombic phase. As determined by impedance spectroscopy, the ionic conductivities of Sm 2 TiO 5 and Sm 2 Ti 2 O 7 at 1000° C are 1.3 × 10 -3 and 1.8 × 10 -4 S cm -1 , and the activation energies of the bulk and grainboundary conductivities of the materials are 1.04 and 1.24 eV for Sm 2 TiO 5 and 1.69 and 1.80 eV for Sm 2 Ti 2 O 7 .

Research paper thumbnail of L. P. Lyashenko, L. G Shcherbakova, D. A. Belov, E. I. Knerel’man, and N. N. Dremova. Synthesis and Electrical Properties of Gd2MO5 (M = Zr, Hf) // Inorganic Materials. 2010. V. 46. № 12. PP. 1341-1347

Inorganic Materials, 2010

ABSTRACT Polycrystalline Gd2ZrO and Gd2HfO5 have been prepared by heat-treating coprecipitated ox... more ABSTRACT Polycrystalline Gd2ZrO and Gd2HfO5 have been prepared by heat-treating coprecipitated oxide mixtures, and their order-disorder phase transitions have been studied in the range 20–1600°C. The materials have been shown to consist of nanostructured grains with a nanodomain size of ∼40 nm. Their electrical conductivity has been determined by impedance spectroscopy in air between 300 and 1000°C. The 1000°C conductivities of Gd2ZrO5 and Gd2HfO5 are 3.7 × 10−3 and 1.8 × 10−3 S/cm, and the respective effective activation energies are 1.37 and 1.56 eV.

Research paper thumbnail of Study of solid solutions in the TiO2?Sc2O3 system by the method of x-ray photoelectron spectroscopy

Journal of Structural Chemistry, 1980

Research paper thumbnail of Mechanism of formation of barium cuprate-based solid solutions with perovskite-like structure doped with cadmium and yttrium oxides

Crystallography Reports, 2002

The influence of Y 2 O 3 and CdO content on the phase composition, structure, and electrical prop... more The influence of Y 2 O 3 and CdO content on the phase composition, structure, and electrical properties of Y 2 O 3 -CdO-BaO-CuO ceramics was studied. The concentration limits of the existence of the orthorhombic perovskite-like Y x Ba 2x Cd y Cu 1y O 3 + δ solid solutions (where 0.20 ≤ x ≤ 0.37 and y ≤ 0.2) and their unitcell parameters are determined.

Research paper thumbnail of Effect of a Nonequilibrium State on Phase Relations in the System TiO 2 –Sc 2 O 3 (40–50 mol % Sc 2 O 3 )

Inorganic Materials, 2004

The phase transitions in TiO2–Sc2O3 (40–50 mol % Sc2O3) samples prepared from coprecipitated and ... more The phase transitions in TiO2–Sc2O3 (40–50 mol % Sc2O3) samples prepared from coprecipitated and mechanically activated oxide mixtures are studied. It is shown that heat treatment below 1000°C leads to the formation of nonstoichiometric, metastable cubic phases with a distorted fluorite structure. With increasing temperature, this structure transforms into a stable fluorite-like structure through (low-symmetry) orthorhombic and hexagonal phases, which

Research paper thumbnail of Defect structure of xY2O3 · (1 − x)TiO2 (x = 0.5–0.58) solid solutions

Inorganic Materials, 2014

X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xY... more X ray diffraction characterization with monochromatic synchrotron X rays has demonstrated that xY 2 O 3 ⋅ (1 -x)TiO 2 (x = 0.5-0.58) solid solutions consist of a fluorite like (Fm3m) disordered phase and a nanoscale ( 40-1000 nm) pyrochlore like (Fd3m) ordered phase of the same composition, coherent with the disordered phase. In the composition range of the solid solutions (0.5 ≤ x ≤ 0.58), the lattice parameter of the fluorite like phase follows Vegard's law. The formation of nanodomains with different degrees of order is shown to be caused by the internal strain due to the high density of structural defects in their unit cells. The materials obtained in this study possess enhanced sorption capacity and can be used as catalysts, catalyst sup ports, gas sensors, etc.