Processing and Characterization of (1-x)(Na1/2Bi1/2)TiO3 - xLa(Mg1/2Ti1/2)O3 Ceramics

2006 ◽  
Vol 514-516 ◽  
pp. 250-254 ◽  
Author(s):  
Andrei N. Salak ◽  
Nikolai P. Vyshatko ◽  
Andréi L. Kholkin ◽  
Victor M. Ferreira ◽  
Nikolay M. Olekhnovich ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Bismuth Titanate ◽  
Lead Free ◽  
Dielectric Characteristics ◽  
Compositional Evolution ◽  
Evolution Of Structure ◽  
Permittivity Maximum

Lead-free relaxor ceramics based on sodium-bismuth titanate, (1-x)(Na1/2Bi1/2)TiO3 - xLa(Mg1/2Ti1/2)O3 [(1-x)NBT-xLMT] (0≤x≤0.25), were prepared by both the conventional mixed oxide method and by the Pechini route, and their crystal structure and dielectric properties were investigated. All the compositions studied were found to possess a rhombohedrally distorted crystal lattice at room temperature. A distortion degree of the unit cell decreases and its volume increases with LMT content. The temperature of the dielectric permittivity maximum does not change with increasing substitution rate. As x is increased, the frequency-dependent dielectric peaks are flattened. The compositional evolution of structure and dielectric characteristics of the ceramics obtained are analysed and discussed in respect to size, charge and polarizability of the cations involved.

Dielectric and Piezoelectric Properties of (Na,Ba)(Nb,Ti)O3 Lead-Free Piezoelectric Ceramics

2010 ◽  
Vol 445 ◽  
pp. 55-58 ◽  
Author(s):  
Rintaro Aoyagi ◽  
Makoto Iwata ◽  
Masaki Maeda
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Dielectric And Piezoelectric Properties

(Na1-xBax)(Nb1-xTix)O3 (NNBTx; x=0.0-0.21) solid-solution ceramics were synthesized and their crystal structure, dielectric properties and piezoelectric properties were investigated. The crystal structure at room temperature of NNBTx varied from orthorhombic to tetragonal with increasing BaTiO3 content x. The phase boundary between orthorhombic and tetragonal at room temperature was confirmed BT content between x=0.08 and 0.09. For x>0.05, it was found that the Curie temperature was decreased with increasing x. The highest electromechanical coupling factor, kp, and the largest piezoelectric constant, d33, were obtained at x=0.09-0.10.

Structural Systematics of Rare Earth Complexes. VII. Crystal Structure of Bis(2,2'/6',2␛-Terpyridinium) Octaaquaterbium(III) Heptachloride Hydrate

1994 ◽  
Vol 47 (2) ◽  
pp. 391 ◽  
Author(s):  
CJ Kepert ◽  
BW Skeleton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Structural Characterization ◽  
Title Compound ◽  
Room Temperature ◽  
Chloride Ions ◽  
Full Matrix ◽  
X Ray

The room-temperature single-crystal X-ray structural characterization of the title compound (tpyH2)2[Tb(OH2)8]Cl7.~2⅓H2O is recorded. Crystals are triclinic, Pī , a 17.063(5), b 16.243(3), c 7.878(3) Ǻ, α 84.78(2), β 84.39(3), γ 87.81(2)°, Z = 2 formula units; 3167 'observed' diffractometer reflections were refined by full-matrix least-squares procedures to a residual of 0.057. Notable features of interest of the compound are the 'chelation' of chloride ions by the terpyridinium cations , and the existence of a free [Tb(OH2)8]2+ cation in the presence of an abundance of chloride ions.

Effect of Sintering Temperature on Structure and Dielectric Properties of Lead Free K0.5Na0.5NbO3 Prepared via Hot Isostatic Pressing

2017 ◽  
Vol 888 ◽  
pp. 42-46 ◽  
Author(s):  
Fatin Khairah Bahanurdin ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Hot Isostatic Pressing ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Tangent Loss ◽  
Isostatic Pressing ◽  
Tan Δ

In this research, alkaline niobate known as K0.5Na0.5NbO3 (KNN) lead-free piezoelectric ceramic was synthesis by solid state reaction method which pressing at different sintering temperatures (1000 °C and 1080 °C) prepared via hot isostatic pressing (HIP)). The effect of sintering temperature on structure and dielectric properties was studied. The optimum sintering temperature (at 1080 °C for 30 minutes) using hot isostatic pressing (HIP) was successfully increase the density, enlarge the particle grain size in the range of 0.3 µm – 2.5 µm and improves the dielectric properties of K0.5Na0.5NbO3 ceramics. The larger grain size and higher density ceramics body will contribute the good dielectric properties. At room temperature, the excellent relative permittivity and tangent loss recorded at 1 MHz (ɛr = 5517.35 and tan δ = 0.954), respectively for KNN1080HIP sample. The KNN1080HIP sample is also exhibits highest relative density which is 4.485 g/cm3. The ɛr depends upon density and in this work, the density increase as the sintering temperature increase, which resulting the corresponding ɛr value also increases.

Darstellung, Reaktionen und spektroskopische Charakterisierung von [Os2X8]2-, X = Cl, Br, I, und Kristallstruktur von (PPN)2[Os2I8] · 2 CH2Cl2 / Preparation, Reactions and Spectroscopic Characterization of [Os2X8]2-, X = Cl, Br, I, and Crystal Structure of (PPN)2[Os2I8] · 2 CH2Cl2

1990 ◽  
Vol 45 (10) ◽  
pp. 1416-1424 ◽  
Author(s):  
W. Preetz ◽  
P. Hollmann ◽  
G. Thiele ◽  
H. Hillebrecht
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Triple Bond ◽  
Room Temperature ◽  
Spectroscopic Characterization ◽  
Spectroscopic Constants ◽  
Monoclinic System ◽  
X Ray ◽  
Fine Structures

The triply bonded octahalogenodiosmate(III) anions [Os2X8]2-, previously known with X = Cl, Br, have now been extended to include the iodide with two staggered OsI4 units. This compound was prepared by treating [Os2Cl8]2- with Nal at room temperature in acetone solution. The structure determination by X-ray diffractometry on single crystals of (PPN)2[Os2I8] · 2 CH2Cl2, reveals crystallization in the monoclinic system, space group P21/c with Z = 4. The Os-Os triple bond is with 2.212(1) Å the longest within the three octahalogenodiosmates(III). The Raman spectra show ν(OsOs) at 285, [Os2Cl8]2-; at 287, [Os2Br8]2- and for the iodo compound at 270.1 cm-1 with up to three overtones. The spectroscopic constants are calculated to be ω1 = 270.9 cm-1; X11 = -0.50 cm-1. The 10 Κ UV-VIS spectra of solid [(n-C4H9)4N]2[Os2X8] exhibit δ-π* transitions with maxima at 723, 690 and 643 nm, superimposed by vibrational fine structures with long progressions of 195, 211 and 183 cm-1 for X = Cl, Br, I, respectively. Oxidation of [Os2X8]2-, X = Cl, Br with the corresponding halogen leads to the cleavage of the Os-Os bond, and the dekahalogenodiosmates(IV), [Os2X10]2-, are formed

Solid-Liquid Reaction Synthesis and Characterization of Bioinorganic Complexes of Nicotinic Acid with Antimony(III) and Bismuth(III) Ion

2011 ◽  
Vol 282-283 ◽  
pp. 267-270 ◽  
Author(s):  
Guo Qing Zhong ◽  
Mei Gu ◽  
Yan Zhang
Keyword(s):  
Crystal Structure ◽  
Nicotinic Acid ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
Reaction Synthesis ◽  
Monoclinic System ◽  
Triclinic System ◽  
Liquid Reaction ◽  
Solid Liquid

Bioinorganic complexes of nicotinic acid with trivalent antimony and bismuth are synthesized by solid-liquid reaction at room temperature. The formula of the complexes is Sb(C5H4NCOOH)2Cl3•H2O and Bi(C5H4NCOOH)2Cl3•H2O respectively. The crystal structure of the complex of nicotinic acid and Sb(III) belongs to triclinic system and that of nicotinic acid and Bi(III) belongs to monoclinic system. Thermal analysis can indicate the complex formation between antimony or bismuth ion and nicotinic acid.

An investigation of the polytypical structure of Sr0.2Ba0.8CoO3–δ by neutron powder diffraction

2010 ◽  
Vol 225 (5) ◽  
Author(s):  
Cristina de la Calle ◽  
José Antonio Alonso ◽  
Ainara Aguadero ◽  
Maria Teresa Fernández-Díaz ◽  
Florence Porcher
Keyword(s):  
Crystal Structure ◽  
Thermal Treatment ◽  
Powder Diffraction ◽  
Oxygen Pressure ◽  
Room Temperature ◽  
Neutron Powder Diffraction ◽  
Slow Cooling ◽  
High Oxygen Pressure ◽  
Citrate Precursor

AbstractThe preparation and characterization of two polymorphs of the title composition are described. One hexagonal perovskite, labeled as “H”, was synthesized by thermal treatment of reactive citrate precursor at 900 °C in high oxygen pressure (20 MPa) followed by slow cooling (10 °C/min) to room temperature. This 1D-structure displays aThe evolution of the crystal structure of the 3C phase has been explored

Synthese und Kristallstruktur des Komplexsalzes [Au(tBu2PH)2][HCl2] / Synthesis and Crystal Structure of the Complex Salt [Au(tBu2PH)2][HCl2]

2012 ◽  
Vol 67 (6) ◽  
pp. 543-548 ◽  
Author(s):  
Hans-Christian Böttcher ◽  
Peter Mayer ◽  
Hubert Schmidbaur
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Room Temperature ◽  
Complex Salt ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Large Complex

The synthesis and the characterization of the complex salt [Au(tBu2PH)2][HCl2] (2) resulting from the reaction of hydrogen tetrachloridoaurate(III) hydrate with tBu2PH in dichloromethane at room temperature is reported. Single crystals of 2 have been analyzed by X-ray crystallography: monoclinic, P21=c, Z = 12, a = 12:0805(3), b = 12:3729(4), c = 46:7506(13) Å ; ß = 90:948(2)°; V = 6986:9(3) Å3; T = 173(2) K. The hydrogen bihalide anions [HCl2]- fill the interstices between the large complex cations [Au(tBu2PH)2]+ in the crystal.

scholarly journals Synthesis, Crystal structure, Vibrational, Optical and Dielectric properties Of 2-(2-Aminoethyl)-1-methylpyrrolidinum chloride hexachlorobismuthate (III) monohydrate [C7H18N2]2ClBiCl6.H2O

2013 ◽  
Vol 9 (3) ◽  
pp. 2005-2022 ◽  
Author(s):  
Fayçal Ben Tahar ◽  
Chakib Hrizi ◽  
Slaheddine Chaabouni ◽  
Nassira Chniba-Boudjada ◽  
Nicolas Ratel Ramond ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Three Dimensional ◽  
Free Water ◽  
Unit Cell ◽  
Water Molecules ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Vis Spectroscopy

Synthesis, crystal structure, vibrational and dielectric properties of [C7H18N2]2ClBiCl6.H2O are reported. The compound crystallizes at room temperature in the orthorhombic system, space group P212121, with the following unit cell parameters : a = 7.5500(6) Å, b = 18.3780(2) Å, c = 19.8980(13) Å, V = 2760.9(4) Å3 and four molecules per unit cell. The structure has been solved by three-dimensional Patterson synthesis and refined by least-squares analysis (R1 = 0.0463, wR2 = 0.0764). The crystal structure of the title compound, [C7H18N2]2ClBiCl6.H2O consists of 2-(2-Aminoethyl)-1-methylpyrrolidinium cations, [BiCl6]3- anions, Cl- anions and free water molecules. The Bi(III) cation is coordinated by six Cl- anions in slightly distorsed octahedral geometry. In the crystal, extensive intermolecular N-H…Cl hydrogen bonds occur. The charge-transfer (CT) interactions between 2-(2-Aminoethyl)-1-methylpyrrolidinium cation and the anionic hosts have been revealed by structural analysis and UV-vis spectroscopy. The dielectric properties have been investigated at temperature range from 100 to 300 K at various frequencies (1 KHz – 1 MHz). The evolution of dielectric constant as a function of temperature and frequency of pellet has been investigated in order to determine some related parameters.

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