Библиотека института физики им. Л.В. Киренского СО РАН

Главная

Базы данных

Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Каталог книг и брошюр библиотеки ИФ СО РАН

Каталог журналов библиотеки ИФ СО РАН

Труды сотрудников ИФ СО РАН

Область поиска

в найденном

Формат представления найденных документов:
полный	информационный	краткий

Отсортировать найденные документы по:
автору	заглавию	году издания	типу документа

Поисковый запрос: (<.>S=CRYSTAL-STRUCTURE<.>)

Общее количество найденных документов : 66
Показаны документы с 1 по 20

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Gorev M. V.
Заглавие : Entropy and the mechanism of phase transitions in elpasolites
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2001. - Vol. 43, Is. 1. - P127-136. - ISSN 1063-7834, DOI 10.1134/1.1340198
Примечания : Cited References: 33
Предметные рубрики: ORDERED PEROVSKITE PB2MGTEO6
ELASTIC NEUTRON-DIFFRACTION
THERMODYNAMIC PROPERTIES
CUBIC PEROVSKITES
CRYSTAL-STRUCTURE
HIGH-RESOLUTION
PB2MGWO6
CSPBCL3
Аннотация: The phase transitions in series of crystals with the general formulas A(2)BB'X-6 (X = F, Cl, Br, or CN) and Pb2BB'O-6 that belong to the elpasolite family (space group Fm(3) over bar m) are analyzed. The influence of the size and the shape of cations and anions on the entropy and the mechanism of structural distortions is discussed. (C) 2001 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Flerov I. N., Sciau P.
Заглавие : Heat capacity and the p-T phase diagram of Pb2MgTeO6 elpasolite
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2001. - Vol. 43, Is. 2. - P345-349. - ISSN 1063-7834, DOI 10.1134/1.1349486
Примечания : Cited References: 17
Предметные рубрики: ORDERED PEROVSKITE PB2MGTEO6
CRYSTAL-STRUCTURE
PB2COWO6
PB2MGWO6
Аннотация: The heat capacity of Pb2MgTeO6 is measured in the temperature range 80-300 K. It is found that the heat capacity exhibits an anomaly associated with the phase transition at T-0 = 186.9 K. The thermodynamic parameters of the structural transformation are determined. The effect of hydrostatic pressure up to 0.5 GPa on the phase transition temperature is examined. (C) 2001 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Balaev A. D., Bayukov O. A., Vasil'ev A. D., Velikanov D. A., Ivanova N. B., Kazak N. V., Ovchinnikov S. G., Abd-Elmeguid M. M., Rudenko V. V.
Заглавие : Magnetic and electrical properties of Fe1.91V0.09BO4 warwickite
Разночтения заглавия :авие SCOPUS: Magnetic and electrical properties of Fe1.91V 0.09BO4 warwickite
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2003. - Vol. 97, Is. 5. - P989-995. - ISSN 1063-7761, DOI 10.1134/1.1633954
Примечания : Cited References: 22. - This study was supported in part by the Russian Foundation for Basic Research (project no. 03-02-16286) and by the Federal Program “Integration” (project no. B0017)
Предметные рубрики: ELECTRONIC-STRUCTURE
CRYSTAL-STRUCTURE
FE2OBO3
CHAINS
FE2BO4
FEBO3
Ключевые слова (''Своб.индексиров.''): electric conductivity--magnetic variables measurement--magnetization--single crystals--hopping conductivity--warwickite--iron compounds
Аннотация: We have performed a complex investigation of the structure and the magnetic and electrical properties of a warwickite single crystal with the composition Fe1.91V0.09BO4 . The results of Mossbauer measurements at T = 300 K indicate that there exist "localized" (Fe2+, Fe3+) and "delocalized" (Fe2.5+) states distributed over two crystallographically nonequivalent positions. The results of magnetic measurements show that warwickite is a P-type ferrimagnet below T = 130 K. The material exhibits hopping conductivity involving strongly interacting electrons. The experimental data are analyzed in comparison to the properties of the initial (unsubstituted) Fe2BO4 warwickite. The entire body of data on the electric conductivity and magnetization are interpreted on a qualitative basis. (C) 2003 MAIK "Nauka / Interperiodica".
WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Flerov I. N., Bondarev V. S., Sciau P.
Заглавие : Studies of the thermodynamic properties of the ordered perovskites Pb2CdWO6 and Pb2YbTaO6 within a broad temperature range
Место публикации : Phys. Solid State: AMER INST PHYSICS, 2002. - Vol. 44, Is. 2. - P353-357. - ISSN 1063-7834, DOI 10.1134/1.1451027
Примечания : Cited References: 18
Предметные рубрики: CRYSTAL-STRUCTURE
PB2COWO6
PB2MGWO6
PHASE
HEAT
Аннотация: This paper reports on measurements of the specific heat of Pb2CdWO6 made at temperatures ranging from 80 to 750 K and of Pb2YbTaO6 within the 350- to 700-K temperature range. First-order phase transitions from the cubic phase at 677.3 and 581 K, respectively, were observed, and their thermodynamic characteristics were determined. The entropy change on the phase transitions is close to Rln4 for both compounds. The results obtained are discussed in terms of the model of position disordering of the lead ions. It was established that below 350 K, Pb2CdWO6 can exist in two states, stable and metastable, depending on the sample thermal prehistory. (C) 2002 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : ZEIN N. E., ZINENKO V. I., FEDOROV A. S.
Заглавие : ABINITIO CALCULATIONS OF PHONON FREQUENCIES AND DIELECTRIC-CONSTANTS IN A(4)B(6) COMPOUNDS
Место публикации : Phys. Lett. A: ELSEVIER SCIENCE BV, 1992. - Vol. 164, Is. 1. - P115-119. - ISSN 0375-9601, DOI 10.1016/0375-9601(92)90916-A
Примечания : Cited References: 20
Предметные рубрики: IV-VI COMPOUNDS
CRYSTAL-STRUCTURE
Аннотация: The transverse and longitudinal optical frequencies at q = 0, the dielectric constant and the effective charges are calculated for the A4B6 type family of the semiconducting compounds GeTe, SnTe and PdTe. The calculations are performed in the framework of the density functional method with the use of the norm-conserving "first-principles" pseudopotentials. The estimated ferroelectric phase transition temperatures and a number of other calculated quantities turned out to be in good agreement with the experimental data. The variations of the electronic structure in the row PbTe-GeTe, which promote the ferroelectric phase transition for GeTe, are discussed.
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ivanova N. B., Ovchinnikov S. G., Korshunov M. M., Eremin I. M., Kazak N. V.
Заглавие : Specific features of spin, charge, and orbital ordering in cobaltites
Коллективы : RFBR [09-02-00171-a, 07-02-00226, 09-02-00127]; Federal Agency of Science and Innovation [MK-4278.2008.2]; Presidium of the Russian Academy of Sciences [5, 7]; Leading Science Schools of the Ministry of Education and Science of the Russian Federation [2.1.1/3199]
Место публикации : Phys. Usp.: Turpion Ltd, 2009. - Vol. 52, Is. 8. - P.789-810. - ISSN 1063-7869, DOI 10.3367/UFNe.0179.200908b.0837
Примечания : Cited References: 278. - This work was financially supported by the RFBR (projects 09-02-00171-a, 07-02-00226, and 09-02-00127), the Federal Agency of Science and Innovation (grant MK-4278.2008.2), and the Presidium of the Russian Academy of Sciences Program No. 5, Quantum Physics of Condensed Media (project No. 7). I.M.E.'s work was supported by the program for Leading Science Schools of the Ministry of Education and Science of the Russian Federation (grant 2.1.1/3199).
Предметные рубрики: PEROVSKITE-TYPE OXIDES
METAL-INSULATOR-TRANSITION
HIGH-TEMPERATURE SUPERCONDUCTIVITY
ONE-DIMENSIONAL CA3CO2O6
ELECTRONIC-STRUCTURE
MAGNETIC-PROPERTIES
TRANSPORT-PROPERTIES
STATE TRANSITION
FUEL-CELLS
CRYSTAL-STRUCTURE
Ключевые слова (''Своб.индексиров.''): cobalt oxides--lanthanides--orbital degrees of freedom--orbital ordering--quasi-one-dimensional--spin state--superconducting compounds--theoretical result--calcium--cobalt--lanthanum--oxide minerals--perovskite--spin dynamics--superconductivity--cobalt compounds
Аннотация: Complex cobalt oxides known as cobaltites are reviewed, including LnCoO(3)-based perovskite-structured rare-earth cobaltites (where Ln is lanthanum or a lanthanide), quasi-two-dimensional and quasi-one-dimensional cobaltites of the types LnCo(2)O(5+delta), La2CoO4, and Ca3Co2O8, and NaxCoO2 center dot yH(2)O superconducting compounds. Key experimental and theoretical results are presented, with emphasis on the interplay between charge, spin, and orbital degrees of freedom. Two problems of specific relevance to cobaltites - the spin state instability of Co3+ ions in LnCoO(3), and the nature of superconductivity in NaxCoO2 center dot yH(2)O - are also given significant attention.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Gorev M. V., Sciau P.
Заглавие : Heat capacity and p-T phase diagrams of the ordered perovskites Pb2MgWO6 and Pb2CoWO6
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2000. - Vol. 12, Is. 5. - P.559-567. - ISSN 0953-8984, DOI 10.1088/0953-8984/12/5/304
Примечания : Cited References: 25
Предметные рубрики: CRYSTAL-STRUCTURE
X-RAY
TRANSITIONS
PRESSURE
Аннотация: The heat capacities of Pb2MgWO6 and Pb2CoWO6 and the effect of hydrostatic pressure on the phase transitions have been studied on powdered samples by means of an adiabatic calorimeter and DTA performed under pressure, respectively. Thermodynamic parameters, such as change of total excess entropy, latent hear and hysteresis of the phase transition temperature were determined. Entropies and p-T phase diagrams are discussed in connection with structural data.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Lundin U., Sandalov I., Eriksson O., Johansson B.
Заглавие : Modification of the standard model for the lanthanides
Место публикации : Solid State Commun.: PERGAMON-ELSEVIER SCIENCE LTD, 2000. - Vol. 115, Is. 1. - P7-12. - ISSN 0038-1098, DOI 10.1016/S0038-1098(00)00126-5
Примечания : Cited References: 33
Предметные рубрики: ELECTRONIC-STRUCTURE CALCULATIONS
DENSITY-FUNCTIONAL THEORY
PARTICLE BAND-STRUCTURE
AB-INITIO CALCULATIONS
FERROMAGNETIC NICKEL
COHESIVE PROPERTIES
CRYSTAL-STRUCTURE
MOTT INSULATORS
FERMION SYSTEMS
PR METAL
Ключевые слова (''Своб.индексиров.''): metals--electronic band structure--band structure--elastic moduli--kohn-sham scheme--rare earth elements
Аннотация: We show that incorporation of strong electron correlations into the Kohn-Sham scheme of band structure calculations leads to a modification of the standard model of the lanthanides and that this procedure removes the existing discrepancy between theory and experiment concerning the ground state properties. Within the picture suggested, part of the upper Hubbard f-band is occupied due to conduction band-f-mixing interaction (that is renormalized due to correlations) and this contributes to the cohesive energy of the crystal. The lower Hubbard band has zero width and describes fermionic excitations in the shell of localized f-s. Fully self-consistent calculations (with respect to both charge density and many-electron population numbers of the f-shell) of the equilibrium volume V-0 and the bulk modulus of selected lanthanides have been performed and a good agreement with experiment is obtained. (C) 2000 Elsevier Science Ltd. All rights reserved.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ovchinnikov S. G., Antipina L. Yu., Tomilin F. N., Kuzubov A. A.
Заглавие : Effect of electron correlations on the structure of photoprotein substrates
Коллективы :
Место публикации : JETP Letters. - 2010. - Vol. 91, Is. 9. - P.490-493. - ISSN 0021-3640, DOI 10.1134/S0021364010090122
Примечания : Cited References: 14. - This work was supported by the Russian Foundation for Basic Research (project no. 07-04-00930-a), by the Presidium of the Russian Academy of Sciences (program "Molecular and Cellular Biology"), and by the Siberian Branch, Russian Academy of Sciences (project no. 2).
Предметные рубрики: ANGSTROM RESOLUTION
CRYSTAL-STRUCTURE
AEQUORIN
ENERGY
OBELIN
GAS
Аннотация: The electronic structure and total energy of various isomeric forms of coelenterazine and coelenteramide have been calculated by quantum chemistry methods both in the single-electron approximation and taking into account correlation effects. It has been shown that the inclusion of electron correlations makes it possible to obtain the structure of the coelenteramide close to the experimentally determined structure, as well as to choose the structure of the coelenterazine CLZ(1H) as the most probable isomeric form.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Fokina V. D., Bogdanov E. V., Gorev M. V., Molokeev M. S., Pogorel'tsev E. I., Flerov I. N., Laptash N. M.
Заглавие : Phase transitions in the (NH4)(2)NbOF5 oxyfluoride
Коллективы :
Разночтения заглавия :авие SCOPUS: Phase transitions in the (NH4)2NbOF5 oxyfluoride
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2010. - Vol. 52, Is. 4. - P781-788. - ISSN 1063-7834, DOI 10.1134/S1063783410040189
Примечания : Cited References: 13. - We would like to thank A. A. Udovenko (Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia) for kindly supplied detailed data on the atomic coordinates in the structure of the (NHINF4/INF)INF2/INFNbOFINF5/INF oxyfluoride.This study was supported by the Russian Foundation for Basic Research (project no. 09-02-00062) and the Council on Grants from the President of the Russian Federation for Support of Leading Scientific Schools of the Russian Federation (grant no. NSh-1011.2008.2).
Предметные рубрики: CRYSTAL-STRUCTURE
(NH4)(2)WO2F4
MECHANISM
DISORDER
Аннотация: The thermal and dielectric properties of the (NH4)(2)NbOF5 oxyfluoride have been investigated. It has been established that the structural phase transitions Cmc2(1) - C2 - Ia observed at the temperatures T (1) = 258.0 K and T (2) = 218.9 K exhibit a nonferroelectric nature. The hydrostatic pressure, which stabilizes the initial phase and destabilizes the low-temperature phase, hardly affects the temperature range of stability of the intermediate phase. The model of sequential ordering of the structural elements due to phase transitions has been analyzed using experimental data on the entropies of the phase transitions.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bartolome J., Arauzo A., Kazak N. V., Ivanova N. B., Ovchinnikov S. G., Knyazev Yu. V., Lyubutin I. S.
Заглавие : Uniaxial magnetic anisotropy in Co2.25Fe0.75O2BO3 compared to Co3O2BO3 and Fe3O2BO ludwigites
Разночтения заглавия :авие SCOPUS: Uniaxial magnetic anisotropy in Co2.25Fe0.75O 2BO3 compared to Co3O2BO3 and Fe3O2BO ludwigites
Место публикации : Phys. Rev. B: AMER PHYSICAL SOC, 2011. - Vol. 83, Is. 14. - Ст.144426. - ISSN 1098-0121, DOI 10.1103/PhysRevB.83.144426
Примечания : Cited References: 25. - The authors acknowledge V. V. Rudenko for the oxyborate samples they made and O. A. Bayukov for fruitful discussion. The financial support of Spanish MINCYT, Grant No. MAT08/1077, and the Aragonese E-34 project are acknowledged. Fruitful discussions with F. Bartolome and P. Bordet are acknowledged. The latter is thanked for providing the FeINF3/INFOINF2/INFBOINF3/INF single crystal. Also this study was supported by the Russian Foundation for Basic Research (Project No. 09-02-00171-a), the Federal Agency for Science and Innovation (Rosnauka) (Project No. MK-5632.2010.2), and the Physical Division of the Russian Academy of Science (Program "Strongly Correlated Electrons," Project No. 2.3.1).
Предметные рубрики: CRYSTAL-STRUCTURE
MOSSBAUER
CO3BO5
Аннотация: Magnetic and Mossbauer spectroscopy (MS) measurements have been performed on a single crystal of Co2.25Fe0.75O2BO3 with ludwigite structure. Two magnetic transitions (T-N = 115 K and T-C = 70 K) were traced from the ac susceptibility temperature dependence. The MS spectra as a function of temperature clearly show the onset of magnetic ordering below 115 K. Magnetization measurements on the parent Co3O2BO3 and Fe3O2BO3 compounds have been done for comparison. In Fe3O2BO3 the anisotropy of the different phases has been determined, showing that the anisotropy axis changes from the a to the b axis in the low-temperature antiferromagnetic phase. High magnetic uniaxial anisotropy has been detected for both Co3O2BO3 and Co2.25Fe0.75O2BO3. From the angle-dependent magnetization measurements it is found that in both compounds the easy axis of magnetization is the b [010] axis, where an antiferromagnetic component is superimposed on the main ferromagnetic component. In the c direction the behavior is purely antiferromagnetic. In Co2.25Fe0.75O2BO3 a strong reduction of the remanent magnetization and a very strong increase in coercive field along the b axis with respect to those found in Co3O2BO3 were observed from magnetic hysteresis cycles measured below T-C. The increase of coercive field is caused by the increase of defects upon Co substitution by Fe.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M., Bogdanov E. V., Flerov I. N., Laptash N. M.
Заглавие : Thermal expansion, phase diagrams and barocaloric effects in (NH4)(2)NbOF5
Коллективы :
Разночтения заглавия :авие SCOPUS: Thermal expansion, phase diagrams and barocaloric effects in (NH 4)2NbOF5
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2010. - Vol. 22, Is. 18. - Ст.185901. - ISSN 0953-8984, DOI 10.1088/0953-8984/22/18/185901
Примечания : Cited References: 17. - This work was supported in part by the Krasnoyarsk Regional Foundation for Support of Scientific and Scientific-Technological Investigations and RFBR in the framework of project 'Siberia' (Grant No. 09-02-98001), and the Council on Grants from the President of the Russian Federation for Support of Leading Scientific Schools (project No. Nsh-1011.2008.2).
Предметные рубрики: CRYSTAL-STRUCTURE
SOLID-STATE
OXYFLUORIDE
TRANSITION
ANION
Ключевые слова (''Своб.индексиров.''): antiferromagnets--ferromagnets--heat capacities--high stress--intermediate phase--pippard relations--structural phase transition--transition temperature--uniaxial pressures--financial data processing--phase diagrams--phase transitions--thermal stress--tools--thermal expansion
Аннотация: The thermal expansion along the a, b and c axes of a (NH4)(2)NbOF5 crystal was measured from 120 to 300 K. Anomalies of alpha(T) associated with previously reported phase transitions Cmc2(1) - C-2 - I a were observed along all directions at T-1 = 259.3 K and T-2 = 220.5 K. The analysis of thermal expansion and heat capacity in the frame of the Pippard relations has permitted us to determine the uniaxial pressure derivatives of the transition temperatures dT/d sigma(i). The T-sigma(i) phase diagrams have shown a tendency for the intermediate phase to disappear at high stress along the b and c axes. Intensive and extensive barocaloric effects near the structural phase transitions were found to be comparable with the caloric parameters of some ferroelectrics, ferromagnets and antiferromagnets.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zvyagina G. A., Zhekov K. R., Bezmaternykh L. N., Gudim I. A., Bilych I. V., Zvyagin A. A.
Заглавие : Magnetoelastic effects in terbium ferroborate
Место публикации : Low Temp. Phys. - 2008. - Vol. 34, Is. 11. - P.901-908. - ISSN 1063-777X, DOI 10.1063/1.3009584; \b Физика низких температур
Примечания : Cited References: 17
Предметные рубрики: CRYSTAL-STRUCTURE
ND
Ключевые слова (''Своб.индексиров.''): acoustic wave velocity--antiferromagnetic materials--elastic moduli--exchange interactions (electron)--iron compounds--magnetoelastic effects--solid-state phase transformations--terbium compounds
Аннотация: The behavior of the elastic moduli and sound absorption in a terbium orthoborate single crystal at low temperatures is studied. The components of the tensor of the elastic moduli of this system are determined. A structural phase transition and a transition of the magnetic subsystem into an antiferromagnetically ordered state appear in the temperature dependences of the sound velocities and absorption. The magnetic field dependences of the velocities of transverse sound exhibit singularities in the form of jumps at a magnetic field equal to the field of the spin-flop transition of the antiferromagnetic subsystem. Theoretical analysis shows that the observed behavior of the acoustic characteristics are associated not with the rare-earth subsystem of ferroborate but rather with the renormalization of the exchange interaction between iron ions as a result of the magnetoelastic coupling.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volkov N. V., Sablina K. A., Bayukov O. A., Eremin E. V., Petrakovskii G. A., Velikanov D. A., Balaev A. D., Bovina A. F., Boni P., Clementyev E.
Заглавие : Magnetic properties of the mixed-valence manganese oxide Pb(3)Mn(7)O(15)
Разночтения заглавия :авие SCOPUS: Magnetic properties of the mixed-valence manganese oxide Pb 3Mn7O15
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2008. - Vol. 20, Is. 5. - Ст.55217. - ISSN 0953-8984, DOI 10.1088/0953-8984/20/5/055217
Примечания : Cited References: 16
Предметные рубрики: CRYSTAL-STRUCTURE
PHASE-SEPARATION
Ключевые слова (''Своб.индексиров.''): crystal structure--magnetization--manganese compounds--phase interfaces--x ray diffraction--manganese oxide--space groups--temperature range--single crystals
Аннотация: A Pb(3)Mn(7)O(15) single crystal has been grown by the flux method and studied using x-ray diffraction and magnetization measurements. The crystal is hexagonal (P6(3)/mcm space group, Z = 4) and exhibits a pronounced layered nature. Along the [001] direction (c axis), the structure consists of layers of edge-sharing MnO(6) octahedra. Pairs of Mn atoms occupy the octahedral sites located between layers forming 'bridges' along the c axis, which link neighboring Mn layers. The magnetic properties of the crystal have been investigated using ac and dc magnetization measurements in the temperature range 2-900 K at magnetic fields up to 90 kOe. The experimental data obtained suggest that in the temperature region under study several different magnetic phases can be distinguished. Down to similar to 250 K, the crystal is in the paramagnetic state. Below this temperature, short-range antiferromagnetic ordering apparently starts forming within Mn layers, although a transition to long-range magnetic order occurs at 70 K. The magnetization data obtained leads us to conclude that this state is canted antiferromagnetic with moments lying in the basal plane of the crystal. In addition, below 20 K the crystal undergoes one more magnetic transition that corresponds to spin reorientation.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Popova E. A., Vasiliev A. N., Temerov V. L., Bezmaternykh L. N., Tristan N., Klingeler R., Buchner B.
Заглавие : Magnetic and specific heat properties of YFe3(BO3)(4) and ErFe3(BO3)(4)
Коллективы :
Разночтения заглавия :авие SCOPUS: Magnetic and specific heat properties of YFe3(BO3) 4 and ErFe3(BO3)4
Место публикации : J. Phys.: Condens. Matter: IOP PUBLISHING LTD, 2010. - Vol. 22, Is. 11. - Ст.116006. - ISSN 0953-8984, DOI 10.1088/0953-8984/22/11/116006
Примечания : Cited References: 26. - This work was supported by DFG grants 436 RUS and HE 3439/6 (FOR 520). The authors are indebted to M N Popova and B Z Malkin for valuable discussions.
Предметные рубрики: LINEAR-CHAIN ANTIFERROMAGNETISM
CRYSTAL-STRUCTURE
GDFE3(BO3)(4)
MULTIFERROICS
BA2COS3
ORDER
Ключевые слова (''Своб.индексиров.''): antiferromagnetic orders--basal planes--experimental data--magnetically ordered state--antiferromagnetism--calorimetry--erbium--magnetic moments--single crystals--specific heat--magnetic domains
Аннотация: The present paper reports on the specific heat and magnetization of the YFe3(BO3)(4) and ErFe3(BO3)(4) single crystals. In both compounds, antiferromagnetic order of the iron spins evolves at T-N = 38 K. The experimental data suggest that the magnetic moments are in the basal plane of the trigonal crystal for both compounds. In the magnetically ordered state the crystal is subdivided into three types of domains, the magnetic moments of the Fe3+ ions being aligned along the a axis within each domain. For ErFe3(BO3)(4), two non-equivalent magnetic positions of the Er3+ ions in each domain are observed.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mel'nikova S. V., Isaenko L. I., Gorev M. V., Vasil'ev A. D., Lobanov S. I.
Заглавие : Investigation of the structure, physical properties, and phase transition in SrAlF5
Коллективы :
Место публикации : Phys. Solid State: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2010. - Vol. 52, Is. 3. - P509-514. - ISSN 1063-7834, DOI 10.1134/S1063783410030108
Примечания : Cited References: 16. - This study was supported by the Russian Foundation for Basic Research (project no. 07-02-00442) and the Siberian Branch of the Russian Academy of Sciences within the framework of the Interdisciplinary Integration Project No. 34.
Предметные рубрики: CRYSTAL-STRUCTURE
BEHAVIOR
GROWTH
SRAIF5
Аннотация: Crystals of SrAlF5 have been grown by the Bridgman method from the melt and by sintering of the components. Optical polarization studies and measurements of the thermal expansion and birefringence coefficients have been carried out over a wide temperature range. The electromechanical coefficient d (33) has been measured, and the optical second harmonic, dielectric hysteresis loop, and optical quality of the crystal have been assessed. X-ray diffraction investigations have been performed to identify the revealed compounds. It has been demonstrated that the SrAlF5 crystals obtained under the growth conditions chosen have I4(1)/a symmetry and do not undergo structural phase transitions in the temperature range 100-800 K. Crystalline inclusions of the AlOF oxyfluoride have been revealed in crystals grown with an AlF3 excess. The birefringence of the AlOF crystal is an order of magnitude higher than that of SrAlF5, does not depend on temperature, and has no anomalies up to 800 K.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие

17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Golovnev N. N., Molokeev M. S., Samoilo A. S., Atuchin V. V.
Заглавие : Influence of alkyl substituents in 1,3-diethyl-2-thiobarbituric acid on the coordination environment in M(H2O)2(1,3-diethyl-2-thiobarbiturate)2 M = Ca2+, Sr2+
Место публикации : J. Coord. Chem.: Taylor & Francis, 2016. - Vol. 69, Is. 6. - P.957-965. - ISSN 00958972 (ISSN), DOI 10.1080/00958972.2016.1149168
Примечания : Cited References: 42. - The study was carried out within the public task of the Ministry of Education and Science of the Russian Federation for research engineering of the Siberian Federal University in 2015-2016. V.V.A. is grateful to the Ministry of Education and Science of the Russian Federation for the financial support of the investigation.
Предметные рубрики: CRYSTAL-STRUCTURE
2-THIOBARBITURIC ACID
STRUCTURAL-CHARACTERIZATION
THIOBARBITURIC ACID
THERMAL-PROPERTIES
HYDROGEN-BOND
COMPLEXES
DIFFRACTION
NETWORKS
POLYMERS
Ключевые слова (''Своб.индексиров.''): 1,3-diethyl-2-thiobarbituric acid--alkaline earth metals--coordination compound--x-ray diffraction--thermal analysis
Аннотация: Two new isostructural complexes, [Ca(H2O)2(μ2-Detba-O,O′)2]n (1) and [Sr(H2O)2(μ2-Detba-O,O′)2]n (2) (HDetba = 1,3-diethyl-2-thiobarbituric acid), were synthesized and characterized by single-crystal and powder X-ray diffraction analysis, TG-DSC, FT-IR, and emission spectroscopy. The single-crystal X-ray diffraction data revealed that 1 and 2 are polymeric where M2+ (M = Ca, Sr) is a six-coordinate octahedral binding four Detba− ions and two water molecules. The octahedra are linked through bridging Detba− ions forming a 2-D layer. Two intermolecular hydrogen bonds O–H…S in the crystal form a 3-D net. The comparison of M(Detba)2 and M(Htba)2 (H2tba = 2-thiobarbituric acid) structures showed that the coordination number of metals in M(Detba)2 does not exceed six and there are no π–π interactions, unlike compounds with Htba−; Detba− ions are only bridges in HDetba coordination compounds. Thermal decomposition of 1 and 2 includes dehydration, which mainly ends at 200 °C, and organic ligand oxidation at 300–350 °C with a release of CO2, SO2, H2O, NH3, and isocyanate. Upon excitation at 220 nm, 1 and 2 exhibit an intense emission maximum at 557 nm.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Grossman, Victoria G., Molokeev M. S., Bazarova, Jibzema G., Bazarov, Bair G., Sorokin, Nikolay, I
Заглавие : Structural, thermal and electrical studies of thallium-scandium-hafnium(zirconium) molybdates
Коллективы : Basic Project of BINM SB RAS [0273-2021-0008]; Government of the Russian Federation [075-15-2019-1886]
Место публикации : J. Solid State Chem. - 2022. - Vol. 307. - Ст.122832. - ISSN 0022-4596, DOI 10.1016/j.jssc.2021.122832. - ISSN 1095-726X(eISSN)
Примечания : Cited References: 56. - The work was supported by Basic Project of BINM SB RAS N degrees 0273-2021-0008. Research was conducted using equipment of the CCU BINM SB RAS. Structural analysis of materials in this study was partly sup-ported by the Research Grant No. 075-15-2019-1886 from the Government of the Russian Federation
Предметные рубрики: POSITIVE ELECTRODE MATERIAL
CRYSTAL-STRUCTURE
IONIC-CONDUCTIVITY
Аннотация: Thallium scandium hafnium molybdate Tl5ScHf(MoO4)6 and thallium scandium zirconium molybdate Tl5ScZr(MoO4)6 crystallize in trigonal symmetry with the space group . The compounds are synthesized by sintering the finely powdered simple molybdates mixture in a muffle furnace at 723–823 K for 100 h. The crystal structures of Tl5ScHf(MoO4)6 and Tl5ScZr(MoO4)6 are obtained by Rietveld method. The following unit cell parameters are calculated for Tl5ScHf(MoO4)6: a = 10.62338 (5), c = 38.0579 (2) Å, V = 3719.64 (4) Å3, Z = 6 and for Tl5ScZr(MoO4)6: a = 10.63216 (7), c = 38.0716 (3) Å, V = 3727.14 (5) Å3, Z = 6. The conductivity of the Tl5ScHf(MoO4)6 and Tl5ScZr(MoO4)6 are measured between 293 and 860 K. The ionic conductivity of Tl5ScHf(MoO4)6 and Tl5ScZr(MoO4)6 molybdates are 8 × 10−4 S/cm and 8 × 10−3 S/cm (at 773 K); the activation energy of ionic transfer are 0.8 eV and 0.3 eV respectively.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Molokeev M. S., Su, Binbin, Aleksandrovsky A. S., Golovnev, Nicolay N., Plyaskin M. E., Xia, Zhiguo
Заглавие : Machine learning analysis and discovery of zero-dimensional ns2 metal halides toward enhanced photoluminescence quantum yield
Место публикации : Chem. Mat. - 2022. - Vol. 34, Is. 2. - P.537-546. - ISSN 0897-4756, DOI 10.1021/acs.chemmater.1c02725. - ISSN 1520-5002(eISSN)
Примечания : Cited References: 66. - This work is supported by the National Natural Science Foundation of China (51961145101 and 51972118), International Cooperation Project of National Key Research and Development Program of China (2021YFE0105700), Guangzhou Science and Technology Project (202007020005), and the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01X137). This work is also funded by RFBR according to the research project no. 19-52-80003
Предметные рубрики: RANDOM FOREST
CRYSTAL-STRUCTURE
TIN BROMIDE
CLASSIFICATION
Аннотация: The dependence of photoluminescence quantum yield (PLQY) on the crystal structure of existing zero-dimensional ns2 metal halides is analyzed with the help of principal component analysis and random forest methods. The primary role of the distance between metal ions in different compounds is revealed, and the influence of other structural features such as metal-halogen distance and the distortion of metal-halogen polyhedrons are quantified. Accordingly, the two previously unknown Sb3+-based zero-dimensional metal halides were synthesized to verify the obtained model. Experimental studies of the two compounds demonstrated good agreement with the predictions, and the PLQY of (C10H16N)2SbCl5 is found to be 96.5%. Via machine learning analysis, we demonstrate that concentration quenching is the main factor that determines PLQY for all s2 ion metal halides, which will accelerate the discovery of new luminescence metal halides.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие

20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Denisova L. T., Molokeev M. S., Kargin, Yu F., Ryabov V. V., Chumilina L. G., Belousova, N., V, Denisov V. M.
Заглавие : Structure and thermodynamic properties of the DyGaTi2O7 and EuGaTi2O7 titanates
Коллективы : Russian Federation Ministry of Science and Higher Education [FSRZ-2020-0013]
Место публикации : Inorg. Mater. - 2021. - Vol. 57, Is. 7. - P.733-740. - ISSN 0020-1685, DOI 10.1134/S0020168521070050. - ISSN 1608-3172(eISSN)
Примечания : Cited References: 26. - This work was supported by the Russian Federation Ministry of Science and Higher Education as part of the state research target for the Siberian Federal University federal state autonomous educational institution of higher education, project no. FSRZ-2020-0013
Предметные рубрики: CRYSTAL-STRUCTURE
MAGNETIC-PROPERTIES
STATE
Аннотация: The DyGaTi2O7 and EuGaTi2O7 titanates have been prepared by solid-state reactions in a starting mixture of Dy2O3 (Eu2O3), Ga2O3, and TiO2 via firing in air at temperatures of 1273 and 1573 K, and their crystal structure has been studied by X-ray diffraction. Their high-temperature heat capacity (350-1000 K) has been determined by differential scanning calorimetry. The Cp(T) experimental data have been used to calculate the thermodynamic functions of the titanates.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие