Synthesis of a Series of Heavy Lanthanide(III) Monoporphyrinato Complexes with Tetragonal Symmetry

2017 ◽  
Vol 56 (17) ◽  
pp. 10625-10632 ◽  
Author(s):  
Anas Santria ◽  
Akira Fuyuhiro ◽  
Takamitsu Fukuda ◽  
Naoto Ishikawa
Keyword(s):  
Tetragonal Symmetry ◽  
Heavy Lanthanide

Synthesis of a Series of Monophthalocyaninato Cyclen Heavy Lanthanide(III) Complexes with Tetragonal Symmetry

2017 ◽  
Vol 57 (2) ◽  
pp. 668-675 ◽  
Author(s):  
Kazuro Kizaki ◽  
Motoshi Uehara ◽  
Akira Fuyuhiro ◽  
Takamitsu Fukuda ◽  
Naoto Ishikawa
Keyword(s):  
Tetragonal Symmetry ◽  
Heavy Lanthanide

scholarly journals New Quaternary Chalcogenides Tl2MIIMIV3Se8 and Tl2MIIMIVX4

Proceedings ◽  
2020 ◽  
Vol 62 (1) ◽  
pp. 3
Author(s):  
Andrii Selezen ◽  
Yuri Kogut ◽  
Lyudmyla Piskach ◽  
Lubomir Gulay
Keyword(s):  
Crystal Structure ◽  
Ternary Systems ◽  
Lattice Parameters ◽  
Tetragonal Symmetry ◽  
Orthorhombic Symmetry ◽  
Component Ratio

New quaternary thallium-containing chalcogenides Tl2MIIMIV3X8 and Tl2MIIMIVX4 were synthesized, and their crystal structure was determined by XRD. Three Tl2MIIMIV3X8 chalcogenides crystallize in orthorhombic symmetry (S.G. P212121; Tl2CdGe3Se8 lattice parameters a = 0.76023(9), b = 1.2071(2), c = 1.7474(2) nm), eight isostructural Tl2BIIDIVX4 compounds crystallize in tetragonal symmetry, S.G. I-42m. These compounds form in the quasi-ternary systems Tl2X–MIIX–MIVX2 (X–S, Se, Te) at the component ratio 1:1:1 and 1:1:3 at the sections Tl2MIVX3–BIIX and Tl2MIIMIVX4–MIVX2, respectively. The composition of the Tl2CdGe3Se8 compound was additionally confirmed by SEM and EDS.

scholarly journals Photoconductivity of the Single Crystals Pb4Ga4GeS12 and Pb4Ga4GeSe12

Proceedings ◽  
2020 ◽  
Vol 62 (1) ◽  
pp. 4
Author(s):  
Hadj Bellagra ◽  
Oksana Nyhmatullina ◽  
Yuri Kogut ◽  
Halyna Myronchuk ◽  
Lyudmyla Piskach
Keyword(s):  
Ternary Systems ◽  
Semiconductor Materials ◽  
Tetragonal Symmetry ◽  
Bandgap Energy ◽  
Experimental Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vertical Bridgman ◽  
Symmetry Space ◽  
Symmetry Space Group

Quaternary semiconductor materials of the Pb4Ga4GeS(Se)12 composition have attracted the attention of researchers due to their possible use as active elements of optoelectronics and nonlinear optics. The Pb4Ga4GeS(Se)12 phases belong to the solid solution ranges of the Pb3Ga2GeS(Se)8 compounds which form in the quasi-ternary systems PbS(Se)−Ga2S(Se)3−GeS(Se)2 at the cross of the PbGa2S(Se)4−Pb2GeS(Se)4 and PbS(Se)−PbGa2GeS(Se)6 sections. The quaternary sulfide melts congruently at 943 K. The crystallization of the Pb4Ga4GeSe12 phase is associated with the ternary peritectic process Lp + PbSe ↔ PbGa2S4 + Pb3Ga2GeSe8 at 868 K. For the single crystal studies, Pb4Ga4GeS(Se)12 were pre-synthesized by co-melting high-purity elements. The X-ray diffraction results confirm that these compounds possess non-centrosymmetric crystal structure (tetragonal symmetry, space group P–421c). The crystals were grown by the vertical Bridgman method in a two-zone furnace. The starting composition was stoichiometric for Pb4Ga4GeS12, and the solution-melt method was used for the selenide Pb4Ga4GeSe12. The obtained value of the bandgap energy for the Pb4Ga4GeS12 and Pb4Ga4GeSe12 crystals is 1.86 and 2.28 eV, respectively. Experimental measurements of the spectral distribution of photoconductivity for the Pb4Ga4GeS12 and Pb4Ga4GeSe12 crystals exhibit the presence of two spectral maxima. The first lies in the region of 570 (2.17 eV) and 680 nm (1.82 eV), respectively, and matches the optical bandgap estimates well. The locations of the admixture maxima at about 1030 (1.20 eV) and 1340 nm (0.92 eV), respectively, agree satisfactorily with the calculated energy positions of the defects vs. and VSe.

A New Study of the Acid Rhodo Complex Salt [(NH3)5CrOHCr(NH3)5]Cl5.H2O Shows That the Crystals are Orthorhombic

1997 ◽  
Vol 53 (5) ◽  
pp. 795-802 ◽  
Author(s):  
P. Harris ◽  
H. Birkedal ◽  
S. Larsen ◽  
H. U. Güdel
Keyword(s):  
Hydrogen Bond ◽  
Magnetic Measurements ◽  
Structural Models ◽  
Complex Salt ◽  
Relative Orientation ◽  
Tetragonal Symmetry ◽  
Orthorhombic Space Group ◽  
Satisfactory Description ◽  
Space Groups ◽  
Chloride Monohydrate

Diffraction data recorded at low temperature with Mo K\alpha from two different crystals have been used in the refinement of the structure of the acid rhodo complex salt, \mu-hydroxo-bis[pentaamminechromium(III)] chloride monohydrate [(NH3)5CrOHCr(NH3)5]Cl5.H2O. Several structural models in two different tetragonal space groups have been investigated before a satisfactory description of the structure was obtained. The compound crystallizes in the orthorhombic space group P212121, with a= 16.155 (3), b = 16.154 (3), c = 14.750 (7) Å and Z = 8. The apparent tetragonal symmetry arises due to rotation twinning of the crystals. The diffraction pattern is further complicated by tetragonal pseudo-symmetry of the chromium sites, which means that reflections with l = 2n + 1 are systematically weak. The two independent dimeric cations are involved in slightly different hydrogen-bond patterns. This observation and the relative orientation of the dimers in the crystal is in accordance with spectral and magnetic measurements.

scholarly journals CRYSTAL STRUCTURE OF THE QUATERNARY SEMICONDUCTOR COMPOUND CuFeCrSe3

2019 ◽  
Vol 16 (32) ◽  
pp. 848-853
Author(s):  
Gerzon E. DELGADO ◽  
P. DELGADO-NIÑO ◽  
P. GRIMA-GALLARDO
Keyword(s):  
High Efficiency ◽  
Rietveld Method ◽  
Structural Parameters ◽  
Secondary Phase ◽  
Elemental Abundance ◽  
Tetragonal Symmetry ◽  
Potential Candidate ◽  
Quaternary Compound ◽  
Semiconductor Compound ◽  
Semiconductor System

The compounds with ternary structures of the chalcopyrite family Cu-III-Se2 (III = Al, Ga, In, Cr) form a wide group of semiconductor materials with diverse optical and electrical properties, and the addition of FeSe binary compound produces alloys of the type (Cu-III-Se2)1-x(Fe-Se)x. These types of materials have received increasing attention as promising thermoelectric materials due to their high efficiency, tunable transport properties, high elemental abundance and low toxicity. This work aims to synthesize and characterize structurally a new material belonging to this semiconductor system with x = ½, the quaternary compound CuFeCrSe3. This material was prepared by the melt and anneal technique and its structure was refined from Xray powder diffraction pattern using the Rietveld method. The X-ray powder pattern was mainly composed of CuFeCrSe3 (79.1%) with CuCr2Se4 (20.9%) appearing as secondary phase. The principal phase crystallizes with tetragonal symmetry in the space group P 4 2c (Nº 112), Z = 1, with a = 5.5082(2) Å, c = 10.943(1) Å, V = 332.01(1) Å3. The refinement of 18 instrumental and structural parameters led to Rp = 8.8 %, Rwp = 9.1 %, Rexp = 7.8 % and S = 1.2. This material, belonging to the semiconductor system I-II-III-VI3, crystallizes with a CuFeInSe3-type structure in a normal adamantane-structure. CuFeCrSe3 is a new semiconductor compound, related to the superionic phase CuCrSe2, and can be considered as a potential candidate for mediumtemperature thermoelectric applications.

Study of thef →d transition of heavy lanthanide and actinide ions in crystals using the simple model

2005 ◽  
Vol 242 (12) ◽  
pp. 2503-2508 ◽  
Author(s):  
Chang-Kui Duan ◽  
Shangda Xia ◽  
Michael F. Reid ◽  
Gang Ruan
Keyword(s):  
Simple Model ◽  
Heavy Lanthanide ◽  
Actinide Ions

Ultrastructure, organization and cytochemistry of cytoplasmic crystalline inclusions in Origanum dictamnus L. leaf chlorenchyma cells

1983 ◽  
Vol 64 (1) ◽  
pp. 231-244
Author(s):  
A.M. Bosabalidis ◽  
D. Papadopoulos
Keyword(s):  
Rectangular Prism ◽  
Square Lattice ◽  
Tetragonal Symmetry ◽  
Pepsin Digestion ◽  
Crystalline Inclusions ◽  
Double Helices ◽  
Diffraction Patterns ◽  
Crystallographic Planes

In the cytoplasm of chlorenchyma cells in primary Origanum dictamnus leaves, rectangular prism-like crystals occur, which, as shown by pepsin digestion, are proteinaceous. In sections they usually show either a square lattice or striations running parallel to the short or long axis. In both cases the interspacings are estimated to be about 100 A, suggesting that the arrangement of the crystallographic planes possesses tetragonal symmetry. High magnifications of the crystalline inclusions together with analysis of their diffraction patterns showed that the striations are composed of double helices of protein macromolecules. In leaves 3–4 mm long, eroded crystals are often observed. When leaves are larger than 5 mm, no crystalline bodies can be identified in chlorenchyma cells. It is possible that they represent a storage form of protein, which is used later by the developing cells.

Differential Orbital Expansion in Tetragonal d3 Systems

1982 ◽  
Vol 37 (9) ◽  
pp. 1096-1098
Author(s):  
Patrick E. Hoggard
Keyword(s):  
Tetragonal Symmetry ◽  
Matrix Elements ◽  
Expansion Parameter

Abstract Matrix elements for interelectronic repulsion, including differential orbital expansion, have been calculated for d3 complexes with tetragonal symmetry. The expansion parameter e influences the overall positions of the five components of the 2Eg and 2T1g states and the separation between 2Eg and 2T1g, but is relatively unimportant with respect to the splittings within those states.

Structure and Electrical Properties of BNKT-Based Ceramics

2018 ◽  
Vol 283 ◽  
pp. 147-153 ◽  
Author(s):  
Supalak Manotham ◽  
Pichitchai Butnoi ◽  
Pharatree Jaita ◽  
Tawee Tunkasiri
Keyword(s):  
Grain Size ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Tetragonal Symmetry ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Average Grain Size ◽  
Influence Of Temperature On ◽  
Polarization Electric Field ◽  
Xrd Patterns

In this work, the properties of lead-free 0.92(Bi0.5Na0.42K0.08)TiO3-0.08(BaNb0.01Ti0.99)O3 or 92BNKT-8BNbT ceramic has been investigated. The sample was fabricated by a solid-state reaction technique. The 92BNKT-8BNbT sample was well sintered and dense with high density value of 5.86 g/cm3. X-Ray diffraction (XRD) patterns showed a single perovskite phase with tetragonal symmetry and no impurity or secondary phases. The microstructure was analysed using a scanning electron microscopy (SEM). Average grain size was measured and calculated based on a mean linear intercept method. The ceramics had a cubic-like grain shape with an average grain size of 0.39 µm. The influence of temperature on the dielectric and ferroelectric properties of the ceramic was investigated. The dielectric curves exhibited broad transition peaks at Td and Tm, which were the characteristics of a diffuse phase transition. The polarization-electric field (P-E) hysteresis loop changed from well-saturated at room temperature (RT) to pinched-type loop at high temperature (HT) and the remanent polarization decreased from 21.25 µC/cm2 (at RT) to 5.96 µC/cm2 (at 150 °C).

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