Temperature-dependent crystal structure of ferroelectric Ba2LaTi2Nb3O15

2005 ◽  
Vol 15 (7) ◽  
pp. 798 ◽  
Author(s):  
G. C. Miles ◽  
M. C. Stennett ◽  
I. M. Reaney ◽  
A. R. West
Keyword(s):  
Crystal Structure ◽  
Temperature Dependent

Crystal structure and temperature-dependent properties of Na2H4Ga2GeO8 – a novel gallogermanate

2020 ◽  
Vol 75 (9-10) ◽  
pp. 805-813
Author(s):  
Irma Peschke ◽  
Lars Robben ◽  
Christof Köhler ◽  
Thomas Frauenheim ◽  
Josef-Christian Buhl ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Decomposition Temperature ◽  
Spectroscopic Techniques ◽  
Charge Balance ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Debye Temperatures ◽  
Diffraction Lattice ◽  
Temperature Dependent Properties ◽  
Balance Structure

AbstractSynthesis, crystal structure and temperature-dependent behavior of Na2H4Ga2GeO8 are reported. This novel gallogermanate crystallizes in space group I41/acd with room-temperature powder diffraction lattice parameters of a = 1298.05(1) pm and c = 870.66(1) pm. The structure consists of MO4 (M = Ga, Ge) tetrahedra in four-ring chains, which are connected by two different (left- and right-handed) helical chains of NaO6 octahedra. Protons coordinating the oxygen atoms of the GaO4 tetrahedra not linked to germanium atoms ensure the charge balance. Structure solution and refinement are based on single crystal X-ray diffraction measurements. Proton positions are estimated using a combined approach of DFT calculations and NMR, FTIR and Raman spectroscopic techniques. The thermal expansion was examined in the range between T = 20(2) K and the compound’s decomposition temperature at 568(5) K, in which no phase transition could be observed, and Debye temperatures of 266(11) and 1566(65) K were determined for the volume expansion.

scholarly journals Crystal Structure Dependence of Antiferromagnetic Coupling in FE/SI Multilayers

1995 ◽  
Vol 384 ◽  
Author(s):  
R. P. Michel ◽  
A. Chaiken ◽  
M. A. Wall
Keyword(s):  
Crystal Structure ◽  
Magnetic Coupling ◽  
Antiferromagnetic Coupling ◽  
Temperature Dependent ◽  
Layered Systems ◽  
Metal Insulator ◽  
Structure Dependence ◽  
Metallic Conductor ◽  
Metal Metal ◽  
Cscl Structure

ABSTRACTRecent reports of temperature dependent antiferromagnetic coupling in Fe/Si multilayers have motivated the generalization of models describing magnetic coupling in metal/metal multilayers to metal/insulator and metal/semiconductor layered systems. Interesting dependence of the magnetic properties on layer thickness and temperature are predicted. We report measurements that show the antiferromagnetic (AF) coupling observed in Fe/Si multilayers is strongly dependent on the crystalline coherence of the silicide interlayer. Electron diffraction images show the silicide interlayer has a CsCl structure. It is not clear at this time whether the interlayer is a poor metallic conductor or a semiconductor so the relevance of generalized coupling theories is unclear.

scholarly journals Temperature Dependence of Electrical Properties and Crystal Structure of 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Qian Li ◽  
Yun Liu ◽  
Andrew Studer ◽  
Zhenrong Li ◽  
Ray Withers ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electrical Properties ◽  
Dielectric Permittivity ◽  
Neutron Diffraction ◽  
Electrical Measurement ◽  
Temperature Dependent ◽  
Electromechanical Properties ◽  
Polar Order

We characterized the temperature dependent (~25–200°C) electromechanical properties and crystal structure of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3single crystals usingin situelectrical measurement and neutron diffraction techniques. The results show that the poled crystal experiences an addition phase transition around 120°C whereas such a transition is absent in the unpoled crystal. It is also found that the polar order persists above the maximum dielectric permittivity temperature at which the crystal shows a well-defined antiferroelectric behavior. The changes in the electrical properties and underlying crystal structure are discussed in the paper.

On the Crystal Structure and Temperature Dependent Spectroscopy of the UV-C Emitting Phosphor Sr3(BO3)2:Pr3+,Na+

2021 ◽  
Vol 230 ◽  
pp. 117765
Author(s):  
Jan-Niklas Keil ◽  
Christian Paulsen ◽  
Rainer Pöttgen ◽  
Thomas Jüstel
Keyword(s):  
Crystal Structure ◽  
Temperature Dependent ◽  
Uv C

Temperature-dependent Changes of the Crystal Structure of Li2B4O7

2008 ◽  
Vol 634 (14) ◽  
pp. 2601-2607 ◽  
Author(s):  
Natalia Sennova ◽  
R. S. Bubnova ◽  
G. Cordier ◽  
B. Albert ◽  
S. K. Filatov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Temperature Dependent

Synthesis, x-ray crystal structure, and temperature-dependent NMR spectrum of tetraethylammonium (.alpha.-methoxybenzyl)pentacarbonyltungstate

1978 ◽  
Vol 17 (11) ◽  
pp. 3045-3049 ◽  
Author(s):  
Charles P. Casey ◽  
Stanley W. Polichnowski ◽  
Hendrik E. Tuinstra ◽  
Loren D. Albin ◽  
Joseph C. Calabrese
Keyword(s):  
Crystal Structure ◽  
Temperature Dependent ◽  
Nmr Spectrum ◽  
X Ray

Crystal structure, electrical, and thermal properties of Ca0.5Th0.5VO4

2009 ◽  
Vol 24 (12) ◽  
pp. 3551-3558 ◽  
Author(s):  
S.J. Patwe ◽  
S. Nagabhusan Achary ◽  
Avesh K. Tyagi
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Rietveld Refinements ◽  
Cell Parameters ◽  
Expansion Behavior ◽  
High Temperature Xrd ◽  
Zircon Type

Ca0.5Th0.5VO4 was prepared by a solid-state reaction of component oxides and characterized by powder x-ray diffraction (XRD) at ambient and higher temperatures and impedance spectroscopy. Crystal structure was refined by Rietveld refinements from powder XRD data. At room temperature, Ca0.5Th0.5VO4 has a zircon-type tetragonal (I41/amd) lattice with unit cell parameters: a = 7.2650(1) and c = 6.4460(1) Å. Despite the large charge difference, Ca2+ and Th4+ are statistically distributed over a single site. The crystal structure of Ca0.5Th0.5VO4 is built from the (Ca/Th)O8 (bisdisphenoid) and VO4 tetrahedra. The in situ high-temperature XRD studies on Ca0.5Th0.5VO4 revealed anisotropic thermal expansion behavior with coefficients of thermal expansion αc = 10.96 × 10−6/°C and αa = 5.32 × 10−6/°C. The impedance measurements carried out in the temperature range from ambient to 800 °C indicate semiconducting behavior with appreciable ionic conductivity above 400 °C. The activation energy obtained from the temperature-dependent AC conductivity data is ∼1.37 eV. In wider range of frequencies and temperatures, the relative permittivity of approximately 50 to 60 is observed for Ca0.5Th0.5VO4.

Structure and Magnetic Properties of a Dinuclear Complex with Iron(III) in Octahedral and Pyramidal Coordination

1994 ◽  
Vol 49 (9) ◽  
pp. 1239-1242 ◽  
Author(s):  
Ayhan Elmali ◽  
Yalcin Elerman ◽  
Ingrid Svoboda ◽  
Hartmut Fuess ◽  
Klaus Griesar ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Moment ◽  
Effective Magnetic Moment ◽  
Dinuclear Complex ◽  
Monoclinic Space Group ◽  
Temperature Dependent ◽  
Space Group ◽  
Binuclear Unit

[FeL(MeOH)Cl]2 (L = N-(2-hydroxyphenyl)salicylaldimine) was synthesized and its crystal structure determined, [C27H20N 2O5Cl2Fe2], monoclinic, space group P21/c, a = 9.528(1), b = 7.684(1), c = 18.365(2) Å, β = 109.83(1)°, V = 1264.8 Å3, Z = 2. Two identical [FeL(MeOH)Cl] fragments, related by an inversion centre, are combined by the two bridging O atoms, to form a binuclear unit. The iron(III) centers are separated by 3.163(2) Å and weakly antiferromagnetically coupled (J = -8 .0 (1 ) cm-1), which follows from temperature - dependent magnetic susceptibility measurements in the range 4.2 to 288 K. The effective magnetic moment per iron(III) is μeff = 7.4 μB at 288 K

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