P 59 Physico-chemical foundations of using lead and tin(II) ferrocyanides as the precursores for synthesis of molecular magnets [Text] / E. V. Polyakov, L. G. Maximova, T. A. Denisova, V. G. Zubkov, A. P. Tyutyunnick, N. A. Zhuravlev, O. N. Leonidova // Physics and chemistry of novel materials: 4th Bilateral Russian-German Symposium (Febr. 24-March 1, 1999): Progr. and abstr. - 1999. - P2.26 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): Pb -- СВИНЕЦ -- Sn -- ОЛОВО -- ФЕРРОЦИАНИДЫ -- СВОЙСТВА МАГНИТНЫЕ -- МАГНИТНЫЕ СВОЙСТВА -- ФИЗИКО-ХИМИЧЕСКИЕ СВОЙСТВА -- СВОЙСТВА ФИЗИКО-ХИМИЧЕСКИЕ -- ХИМИЯ ТВЕРДОГО ТЕЛА -- СИНТЕЗ |
S 46 Semiconductor-metal transition in defect lithium cobaltite [Текст] / D. G. Kellerman, V. R. Galakhov, A. S. Semenova, Ya. N. Blinovskov, O. N. Leonidova // Physics of the Solid State. - 2006. - Vol. 48, № 3. - С. 548-556. - Библиогр. : с. 555 (36 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ПЕРЕХОД ПОЛУПРОВОДНИК - МЕТАЛЛ -- КОБАЛЬТИТ ЛИТИЯ Аннотация: The magnetic susceptibility, electrical conductivity, and x-ray photoelectron and x-ray absorption spectra of defect lithium cobaltites of the general formula Li1−xCoO2 are investigated. It is found that, for lithium cobaltites with x> 0.25, the magnetic susceptibility increases abruptly and the conductivity type changes at T~ 150 K. The assumption is made that the semiconductor–metal transition in defect lithium cobaltite is caused by the increase in the diffusion mobility of lithium ions with an increase in the temperature when there is a correlation between spatial distributions of lithium vacancies and “electron” holes Полный текст |
M 61 Metatitanic acid: synthesis and properties [Текст] / T. A. Denisova, L. G. Maksimova, E. V. Polyakov, N. A. Zhuravlev, S. A. Kovyazina, O. N. Leonidova, D. F. Khabibulin, E. I. Yur`eva // Zhurnal Neorganicheskoi Khimii. - 2006. - Vol. 51, № 5. - С. 757-766 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
C 91 Crystal structure and thermal behavior of a new lead nitrate cyanoferrate(III) [Текст] / T. A. Denisova, S. A. Gromilov, I. A. Baidina, L. G. Maksimova, O. N. Leonidova, N. A. Zhuravlev // Zhurnal Neorganicheskoi Khimii. - 2005. - Vol. 50, № 5. - С. 830-834 Рубрики: ХИМИЧЕСКИЕ НАУКИ |
T 44 Thermodynamic and structural properties of PrBaCo2O5+delta [Text] / I. A. Leonidov, M. V. Patrakeev, E. B. Mitberg, O. N. Leonidova, V. L. Kozhevnikov // Inorganic Materials. - 2006. - Vol. 42, № 2. - P196-201 : il. - Библиогр. : с. 201 (4 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ТЕРМОДИНАМИЧЕСКИЕ СВОЙСТВА -- КОБАЛЬТИТ ПРАЗЕОДИМА -- КАЛОРИМЕТРИЧЕСКИЕ ИССЛЕДОВАНИЯ -- ТИТРОВАНИЕ Аннотация: The oxygen content of the double cobaltite PrBaCo2O5 +δ was determined by coulometric titration in broad temperature and oxygen pressure ranges, and the partial thermodynamic functions of oxygen were evaluated. The results on the nonstoichiometry and structural properties of PrBaCo2O5 +δ demonstrate that, at 5 +δ< 5.3, this cobaltite has a high-temperature phase with lattice parameters a = 11.774 Å, b = 11.932 Å, and c = 7.609 Å. The composition dependences of ΔH(O) and ΔS(O) indicate that the 3ap×3ap×2ap orthorhombic structure persists in the range 5.15≤5 +δ≤5.30. Some of the Co3+ ions are shown to disproportionate according to the scheme 2Co(3+)= Co(2+)+CoÓ4+ Полный текст |
L 55 Leonidova, O. N. Synthesis and electrophysical properties of cation conductorsSr3 - 3xLa2x(V1 -yPyO4)2 with palmierite structure / O. N. Leonidova, E. I. Leonidova // Solid State Ionics. - 2008. - vol. 179, № 1-6. - p. 188-191 : il. - Bibliogr. : p. 191 (8 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): КАТИОННЫЙ ПЕРЕНОС -- ПРОВОДИМОСТЬ -- ФАЗОВЫЕ ПЕРЕХОДЫ -- ОРТОВАНАДАТ СТРОНЦИЯ -- ОРТОФОСФАТ СТРОНЦИЯ Аннотация: The solid solutions Sr2.4La0.4(V1 - yPyO4)2 with palmierite structure were synthesized and characterized. The electrical conductivity was measured depending on temperature and partial pressure of oxygen. Both studies were carried out in the range of partial oxygen pressure 10.15.0.5atm at temperatures 400.1200C. Thermal expansion tests were carried out in air within 20.1200C. The cation transport over Sr2 positions is responsible??for the ion conductivity below 950 C. The disordering of palmierite structure in Sr2.4La0.4(V1 - yPyO4)2, where y>=0.3, near 1000 ‹C is accompanied by the conductivity increase in about two times and by the decrease of thermal expansion coefficient. These changes are explained as manifestation of interstitial strontium cations. The substitution of vanadium by phosphorus results in the increase in thermodynamic stability |
S 89 Structural aspects of lithium transferin solid electrolytes Li2xZn2–3xTi1+xO4 (0.33 / I. A. Leonidov, O. N. Leonidova, R. F. Samigullina, M. V. Patrakeev // Journal of Structural Chemistry. - 2004. - Vol. 45, № 2. - P.262-268 : ил. - Bibliogr. : p. 268 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): РАСТВОРЫ ТВЕРДЫЕ -- ЭЛЕКТРОЛИТЫ ТВЕРДЫЕ -- ЛИТИЙ -- ПРОВОДИМОСТЬ -- ШПИНЕЛИ Аннотация: Solid solutions Li2xZn2–3xTi1+xO4, where x = 1/3, 1/2, 3/5, 2/3, were studied by powder X-ray diffractometry and differential thermal analysis. Conductivity measurements have been performed in the gas phase at different temperatures and oxygen pressures. Distribution of cations over the sites of the spinel structure has been determined. Conductivity increases substantially with lithium concentration. The high lithium conductivity of Li3Zn0.5Ti4O10 (x = 3/5) and Li4Ti5O12 (x = 2/3) is the result of two sequential phase transitions associated with different lithium distributions in high-temperature phases with defective NaCl type structures. Possible routes of lithium ion transport are discussed and rationalized based on the conductivity and crystal data Полный текст |
H 65 High-Temperature Raman Spectroscopy and Phase Transformations in Phosphates and Vanadates Ca3 – 3xNd2x(AO4)2 (A = P, V; 0 / S. A. Kovyazina, L. A. Perelyaeva, O. N. Leonidova, I. A. Leonidov, A. L. Ivanovskii // Crystallography Reports. - 2004. - Vol. 49, № 2. - P.211-214 : il. - Bibliogr. : p. 214 (10 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): СПЕКТРОСКОПИЯ РАМАНОВСКАЯ -- ФАЗОВЫЕ ПЕРЕХОДЫ -- ФОСФАТЫ -- ВАНАДАТЫ Аннотация: The phases of variable composition Ca3 - 3x Nd2x(AO4)2 (A = P, V; 0<=x<=0.14) based on calcium orthophosphate or orthovanadate are studied by Raman spectroscopy. The influence of the composition and temperature on the structural features of these compounds is considered. The changes observed in the Raman spectra at high temperatures are associated with the reversible phase transition due to the redistribution of calcium over different positions and partial reorientation of the AO4 tetrahedra \\\\Expert2\\nbo\\Crystallography Reports (Кристаллография)\\2004, v.49, N 2, p. 211-214.pdf |
T 44 The Effect of Divalent Cations on the Structural Parameters, Phase Transitions, and Electrical Conductivity of Oxygen Conductors Based on LaGaO / I. A. Leonidov, I. V. Baklanova, L. A. Perelyaeva, O. N. Leonidova, R. F. Samigullina, V. L. Kozhevnikov // Doklady Chemistry. - 2009. - Vol. 427, № 2. - P. 194-198 : il. - Bibliogr. : p. 198 (10 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): КАТИОНЫ -- ФАЗОВЫЕ ПЕРЕХОДЫ -- ЭЛЕКТРОПРОВОДНОСТЬ -- ПЕРОВСКИТОПОДОБНЫЕ ОКСИДЫ \\\\Expert2\\nbo\\Doklady Chemistry\\2009, v. 427, N 2, p. 194-198.pdf |
F 42 Ferroelectric–Ionic Conductor Phase Transitions in Optical Nonlinear Ca9R(VO4)7 Vanadates / B. I. Lazoryak, A. A. Belik, S. Yu. Stefanovich, V. A. Morozov, A. P. Malakho, O. V. Baryshnikova, I. A. Leonidov, O. N. Leonidova // Doklady Physical Chemistry. - 2002. - vol. 384, № 4-6. - P. 144-148 : il. - Bibliogr. : p. 148 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ФЕРРОЭЛЕКТРИКИ -- ИОННАЯ ПРОВОДИМОСТЬ -- ФАЗОВЫЙ ПЕРЕХОД -- ВАНАДАТЫ \\\\Expert2\\nbo\\Doklady Physical Chemistry\\2002, V. 384, N 4-6, p.144-148.pdf |
L 55 Leonidov, I. A. Electronic Conductivity of Sr3 - 3xLa2xvacancyx(VO4)2 Solid Solutions / I. A. Leonidov, O. N. Leonidova, V. K. Slepukhin // Inorganic Materials. - 2000. - Vol. 36, № 1. - P. 72-75 : il. - Bibliogr. : p. 75 (8 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ЭЛЕКТРОННАЯ ПРОВОДИМОСТЬ -- РАСТВОРЫ ТВЕРДЫЕ -- ВАНАДАТЫ -- СТРОНЦИЙ -- ЛАНТАН Аннотация: The electronic conductivity of Sr 3 3xLa2x[vacancylx(VO4)2 solid solutions was measured at oxygen pressures from 10 -13 tO 105 Pa and temperatures from 1070 to 1270 K, and their band gap was determined as a function of composition. The activation energy (~2.85 eV) and enthalpies of electron generation (=,4.2 eV) and migration (~-0.75 eV) were determined. A correlation between the band gap and electronic conductivity of the solid solutions was revealed |
S 89 Structure and Transport Properties of Li1- 2xCO1 + xVO4 Lithium Ionic Conductors / I. A. Leonidov, R. F. Samigullina, O. N. Leonidova, B. V. Slobodin, M. V. Patrakeev, O. V. Koryakova // Inorganic Chemistry. - 2000. - Vol. 36, № 9. - P. 942-946 : il. - Bibliogr. : p. 945-946 (10 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): СВОЙСТВА ТРАНСПОРТНЫЕ -- ПРОВОДНИКИ ИОННЫЕ -- ШПИНЕЛИ -- ВАНАДАТЫ -- ЛИТИЙ Аннотация: Li 1-x 2xCo 1 + xVO4 (0 < x <= 0.25) spinel solid solutions were synthesized and characterized by x-ray diffraction and IR spectroscopy. The materials were found to have a cubic structure in the composition range 0 < x <= 0.1 and an orthorhombic structure for x > 0.1. The observed lattice distortions were shown to correlate with Co content. The conductivity of the solid solutions was measured as a function of temperature and oxygen partial pressure. The ionic and electronic (n and p) conductivities were determined. The conduction in the solid solutions was shown to be dominated by Li + ions Полный текст |
P 93 Proton Conductivity in H2-x(NH4)xV9Mo3O32.5-delta · nH / I. A. Leonidov, V. L. Volkov, G. S. Zakharova, O. N. Leonidova // Inorganic Materials. - 2002. - Vol. 38, № 11. - P. 1178-1182 : il. - Bibliogr. : p. 1182 (13 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ПРОВОДИМОСТЬ ПРОТОННАЯ -- КСЕРОГЕЛИ -- ОКСИД ВАНАДИЯ Аннотация: The electrical conductivity of H2- x(NH4)xV9Mo3O32.5-delta · nH2O xerogel films containing different amounts of ammonium ions and water was measured as a function of temperature. The results demonstrate that, in a wide temperature range, the proton conductivity of the films reaches a maximum at x = 1.5. The activation energy of conductivity in the films, equal to 0.1–0.2 eV at low temperatures, rises upon partial dehydration above 100 °C. The possible mechanisms of proton formation and transport are discussed Полный текст |
C 11 Ca3(VO4)2–LaVO4 Cation Conductors / I. A. Leonidov, O. N. Leonidova, L. L. Surat, R. F. Samigullina // Inorganic Materials. - 2003. - Vol. 39, № 6. - P. 616-620 : il. - Bibliogr. : p. 620 (20 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ФАЗОВОЕ РАВНОВЕСИЕ -- ВАНАДАТ КАЛЬЦИЯ -- ВАНАДАТ ЛАНТАНА Аннотация: Experimental data are presented on the electrical conductivity, ionic transference numbers, and phase transitions of Ca3 - xLa2x/3(VO4) 2 (0<= x <= 1) vanadates, which are shown to be Ca ionic conductors. The highest Ca ion conductivity is found in Ca2La2/3(VO4)2 (palmierite structure) at low temperatures and in beta'-Ca3(VO4)2 (whitlockite-like structure) at high temperatures. The mechanisms of Ca2+ transport are discussed Полный текст |
N 52 New Superconductor with a Layered Crystal Structure: Nickel Oxybismuthide LaO1-deltaNiBi / V. L. Kozhevnikov, O. N. Leonidova, A. L. Ivanovskii, I. R. Shein, B. N. Goshchitskii, A. E. Kar'kin // JETP Letters. - 2008. - Vol. 87, № 11. - P649-651 : il. - Bibliogr. : p. 651 (18 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ОКСИВИСМУТИД НИКЕЛЯ -- ОКСИВИСМУТИДЫ МЕТАЛЛОВ -- СВЕРХПРОВОДНИКИ Аннотация: The results of synthesizing a new layered phase—nickel oxybismuthide LaO 1 –δNiBi in a series of superconducting oxypnictides—and its properties in the superconducting and normal states are reported. Although the temperature of the transition of this phase to the superconducting state, Tc~ 4 K, is much lower than the value Tc= 55 K reached at present in oxyarsenide SmO1 –δ FeAs, the similarity of the crystal structures and ρ(T) dependencies indicates that the mechanism responsible for the appearance of the semiconducting state is the same in lanthane oxybismuthide and samarium oxyarsenide Полный текст |
C 91 Crystal structures of double vanadates LiCoVO4 and Li0:5Co1:25VO4 / O. N. Leonidova, V. I. Voronin, I. A. Leonidov, R. F. Samigullina, B. V. Slobodin // Journal of Structural Chemistry. - 2003. - Vol. 44, № 2. - P243-247 : il. - Bibliogr. : p. 247 (9 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ВАНАДАТЫ -- ШПИНЕЛИ -- ЭЛЕКТРОННАЯ СТРУКТУРА -- ЛИТИЙ Аннотация: The crystal structures of vanadates Li1-2xCo1+xVO4 with x = 0 and 0:25 have been studied by a full pattern analysis. It has been shown that in cubic spinel LiCoVO4 (space group Fd3m), the 8a tetrahedral sites contain a majority of vanadium and a small amount of lithium; all cobalt, lithium, and a small amount of vanadium occupy the 16d octahedral sites. Li0.5Co1.25VO4 crystals belong to the rhombic system (Imma space group) with unit cell parameters a = 5:939(1) A, b = 5:810(1) A, and c = 8:303(1) A. On substitution of lithium by cobalt according to the scheme 2Li+ -> Co2+ + , half of the lithium and 70% of the vacancies formed are in the 4a octahedral sites, and one-third of lithium and most of cobalt occupy the 4d octahedral sites. The 4e tetrahedral sites are completely occupied by vanadium and lithium in a ratio of 0:92=0:08. The interatomic distances in LiCoVO4 and Li0.5Co1.25VO4 are calculated, and the sizes of lithium ion transport channels are evaluated Полный текст |
S 89 Strontium diffusion in Sr3-3xLa2xx(VO4)2 solid solutions / O. N. Leonidova, I. A. Leonidov, G. I. Dontsov, A. S. Zhukovskaya // Physics of the Solid State. - 1998. - Vol. 40, № 2. - P200-203 : il. - Bibliogr. : p. 203 (10 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): СТРОНЦИЙ -- ТВЕРДЫЕ РАСТВОРЫ -- КОЭФФИЦИЕНТ ДФФУЗИИ Аннотация: Layer-by-layer radiometric analysis in the temperature range 800–950 °C was used to measure the diffusion coefficients of 90Sr, 45Ca, 133Ba radionuclides in Sr3-3xLa2x vacancy x(VO4)2 (x=50,0.1,0.15,0.2,0.25) solid solutions. It was established that DCa *> .DSr *>.DBa * . An increase in the concentrations of vacancies in the strontium sublattice leads to increased coefficients of diffusion of rare-earth metal cations. The activation energies for radionuclide diffusion were determined. It was shown that M21 cations migrate via Sr(2) positions Полный текст |
S 89 Structure, Ionic Conduction, and Phase Transformations in Lithium Titanate Li4Ti5O12 / I. A. Leonidov, O. N. Leonidova, L. A. Perelyaeva, R. F. Samigullina, S. A. Kovyazina, M. V. Patrakeev // Physics of the Solid State. - 2003. - Vol. 45, № 11. - P2183-2188 : il. - Bibliogr. : p. 2188 (18 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ИОННАЯ ПРОВОДИМОСТЬ -- ФАЗОВЫЙ ПЕРЕХОД -- ТИТАНАТ ЛИТИЯ Аннотация: The spinel structure of lithium titanate Li4Ti5O12 is refined by the Rietveld full-profile analysis with the use of x-ray and neutron powder diffraction data. The distribution and coordinates of atoms are determined. The Li4Ti5O12 compound is studied at high temperatures by differential scanning calorimetry and Raman spectroscopy. The electrical conductivity is measured in the high-temperature range. It is shown that the Li4Ti5O12 compound with a spinel structure undergoes two successive order–disorder phase transitions due to different distributions of lithium atoms and cation vacancies (vacancy, V) in a defect structure of the NaCl type: (Li)8a[Li0.33Ti1.67]16dO4-> [Li vacancy]16c[Li0.33Ti1.67]16dO4 [Li1.33 vacancy0.67]16c[Ti1.67 vacancy0.33]16dO4. The low-temperature diffusion of lithium predominantly occurs either through the mechanism … ->Li(8a)-> V(16c)->V(8a) … in the spinel phase or through the mechanism … Li(16c) ->V(8a)-> V(16c)-> … in an intermediate phase. In the high-temperature phase, the lithium cations also migrate over 48f vacancies: …->Li(16c)-> V(8a, 48f) ->V(16c) ->…. Полный текст |
M 61 Metatitanic Acid: Synthesis and Properties / T. A. Denisova, L. G. Maksimova, E. V. Polyakov, N. A. Zhuravlev, S. A. Kovyazina, O. N. Leonidova, D. F. Khabibulin, E. I. Yur`eva // Russian Journal of Inorganic Chemistry. - 2006. - Vol. 51, № 5. - P691-699 : il. - Bibliogr. : p. 699 (24 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): МЕТАТИТАНОВАЯ КИСЛОТА -- ТИТАНАТ ЛИТИЯ Аннотация: Features of proton-for-lithium ion substitution in monoclinic and pseudocubic lithium titanate are studied by X-ray diffraction, NMR spectroscopy, and Raman spectroscopy. Proton incorporation into the lithium titanate structure decreases the parameter ac of the pseudocubic unit cell from 8.28 Å in Li2TiO3 to ≈ 8.15Å in H2TiO3. Metatitanic acid, like hydrous titania, has weak acid properties, but unlike titania, it sorbs hydrolyzable multicharged cations from aqueous solutions Полный текст |
P 59 Physical and Chemical Properties of Zinc Cyanoferrates(II) / T. A. Denisova, L. G. Maksimova, O. N. Leonidova, N. A. Zhuravlev // Russian Journal of Inorganic Chemistry. - 2009. - Vol. 54, № 1. - P6-12 : il. - Bibliogr. : p. 12 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ЦИАНОФЕРРАТ ЦИНКА Аннотация: Neutral zinc cyanoferrate(II) Zn2Fe(CN)6·2.5H2O and its hydrogen form HZn1.5Fe(CN)6·4.5H2O were synthesized and studied. X-ray diffraction, vibrational spectroscopy, and 1H NMR showed that Zn2Fe(CN)6·2.5H2O in aqueous solutions undergoes reversible hydrolysis. The hydrogen form of zinc cyanoferrate(II) is stable up to ≈200°C. The conductivity of HZn1.5Fe(CN)6·4.5H2O in the temperature range 90–120°C is σ= 10–3.3 S/cm, which is about three orders of magnitude higher than the conductivity of the neutral salt Полный текст |