scholarly journals Czochralski Growth, Magnetic Properties and Faraday Characteristics of CeAlO3 Crystals

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 245 ◽  
Author(s):  
Feiyun Guo ◽  
Qiyuan Li ◽  
Huaimin Zhang ◽  
Xiongsheng Yang ◽  
Zhen Tao ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Circular Dichroism ◽  
Structure Refinement ◽  
Magnetic Behavior ◽  
Czochralski Method ◽  
Czochralski Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Van Vleck ◽  
Abnormal Magnetic Behavior

CeAlO3 crystals were grown in different growth atmospheres by the Czochralski method. The lattice parameters and space group of CeAlO3 crystal were determined by Rietveld structure refinement of X-ray diffraction (XRD) data. The influence of Ce4+ ions in the crystal on the transmittance and crystal color was confirmed by XPS analysis. Magnetization curve at room temperature and temperature dependencies of the magnetic susceptibility in two different directions were measured, indicating that CeAlO3 crystal has remarkable magnetic anisotropy and there is an abnormal magnetic behavior in the vertical <001> direction in the temperature range of 50–150 K. Faraday characteristics of CeAlO3 crystal were investigated at room temperature. Verdet constants of CeAlO3 at 532, 635 and 1064 nm are about 2.1 times as large as those of CeF3. The reason of large Verdet constants was analyzed based on the Van Vleck–Hebb theory and the magnetic circular dichroism (MCD) spectrum.

PHASE STRUCTURE, PIEZOELECTRIC AND MULTIFERRIOC BEHAVIOR OF (K0.48Na0.52)NbO3-Co2O3 PIEZOELECTRIC CERAMICS

2011 ◽  
Vol 04 (03) ◽  
pp. 225-229 ◽  
Author(s):  
WENJUAN WU ◽  
DINGQUAN XIAO ◽  
JIAGANG WU ◽  
JING LI ◽  
JIANGUO ZHU
Keyword(s):  
Room Temperature ◽  
Sintering Temperature ◽  
Magnetic Behavior ◽  
Orthorhombic Phase ◽  
Piezoelectric Ceramics ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Solid State Sintering ◽  
Sintering Method

( K 0.48 Na 0.52) NbO 3-x% Co 2 O 3 (x = 0, 0.03 and 0.05) (KNN-x% Co2O3 ) lead-free piezoelectric ceramics were prepared by the conventional solid-state sintering method. An orthorhombic phase was observed for all KNN-x% Co2O3 ceramics at room temperature, and two phase transitions were confirmed by the high temperature X-ray diffraction and the temperature dependence of the dielectric constant. The Co2O3 greatly improves the density and decreases the sintering temperature of KNN ceramics. The KNN-0.05 mol%Co2O3 ceramic exhibits good properties (d33 = 120 pC/N , k p = 0.41, Q m = 213 and T c = 407°C) and a good age stability. The multiferroic behavior was also observed at room temperature for the KNN-0.05 mol%Co2O3 ceramic, as confirmed by P–E loops and magnetic behavior.

Growth and Magneto-Optical Properties of CaTbAlO4 Crystal

2011 ◽  
Vol 306-307 ◽  
pp. 1722-1727 ◽  
Author(s):  
Man Mei ◽  
Li Li Cao ◽  
Yan He ◽  
Ru Ru Zhang ◽  
Fei Yun Guo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Single Crystal ◽  
Room Temperature ◽  
Near Infrared ◽  
Visible Region ◽  
Czochralski Method ◽  
Optical Devices ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectral

The calcium terbium aluminate (CaTbAlO4) single crystal was grown by Czochralski method successfully for the first time.The structure of the crystal was determined by X-ray diffraction analysis.The transmission spectrum of the crystal was measured at room temperature at the wavelength of 400-1500nm.The specific Faraday rotation of the single crystal was surveyed at room temperature at the wavelength 532nm, 633nm, and 1064nm respectively.The Verdet constants of the CaTbAlO4 crystal are calculated and the results show that the Verdet constants of CaTbAlO4 are around 110% higher than that of TGG in the visible and near-infrared spectral region.Therefore,crystal CaTbAlO4 can be promising material for the fabrication of magneto-optical devices in the visible region.

Ammoniovoltaite, (NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18, a new mineral from the Severo-Kambalny geothermal field, Kamchatka, Russia

2018 ◽  
Vol 82 (5) ◽  
pp. 1057-1077 ◽  
Author(s):  
Elena S. Zhitova ◽  
Oleg I. Siidra ◽  
Dmitry I. Belakovsky ◽  
Vladimir V. Shilovskikh ◽  
Anton A. Nuzhdaev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Structure Refinement ◽  
Geothermal Field ◽  
Water Soluble ◽  
Ammonium Ion ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mössbauer Data

AbstractAmmoniovoltaite, (NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18, is a new voltaite-group mineral. The mineral was discovered at the Severo-Kambalny (North-Kambalny) geothermal field, Kambalny volcanic ridge, Southern Kamchatka, Russia. Ammoniovoltaite forms at ~100°C around geothermal gas/steam vents in association with alunogen, tschermigite and pyrite. Crystals of ammoniovoltaite have euhedral habit, are up to 50 µm in size and grow on alunogen plates. Ammoniovoltaite is black with vitreous lustre, opaque, brittle and water-soluble. Neither cleavage nor parting is found, the fracture is conchoidal. The mineral is isotropic, with the refractive index n = 1.602(2) (589 nm). Infrared spectra contain an absorption band at 1433 cm–1 distinctive for the ammonium ion. The chemical composition is (iron content is given in accordance with Mössbauer data, H2O calculated from a crystal-structure refinement, wt.%): FeO 13.26, Fe2O3 11.58, MgO 2.33, ZnO 0.04, Al2O3 2.74, SO3 47.46, K2O 0.19, CaO 0.11, (NH4)2O 2.96, H2O 16.03, total 96.70. The empirical formula based on S = 12 atoms per formula unit is [(NH4)1.88K0.08Ca0.04]Σ2.00(Fe2+3.74Mg1.17Fe3+0.05Zn0.01)Σ4.97(Fe3+2.89Al0.09)Σ2.98Al1.00(SO4)12.00(H2O)18.00. The crystal structure has been refined to R1 = 0.031 and 0.030 on the basis of 1217 and 1462 unique reflections with I >2σ(I) collected at 100 K and room temperature, respectively. Ammoniovoltaite is the ammonium analogue of voltaite. The mineral is cubic, Fd$\bar{3}$c, a = 27.250(1) Å and V = 20234(3) Å3 (at 100 K); and a = 27.322(1) Å and V = 20396(3) Å3 (at RT), with Z = 16. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 9.67 (74) (022), 7.90 (56) (222), 5.58 (84) (422), 3.560 (100) (731), 3.418 (100) (008) and 2.8660 (37) (931). A brief review of ammonium minerals from various volcanically active geological environments is given.

scholarly journals Structural Evolution according to the temperature of the Compound LiNbO3

2014 ◽  
Vol 70 (a1) ◽  
pp. C1832-C1832
Author(s):  
Charef Tabti ◽  
Abdelkader Chouaih ◽  
Fodil Hamzaoui
Keyword(s):  
Data Structure ◽  
Lithium Niobate ◽  
Room Temperature ◽  
Structure Refinement ◽  
Structural Evolution ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
Reliability Factor ◽  
X Ray ◽  
Evolution Study

Structural evolution of LiNbO3 with temperature. A comparative study was made by X-ray diffraction on a single crystal of lithium niobate (LiNbO3) at low temperature (120K) and room temperature (293K). LiNbO3 is a ferroelectric compound particularly interesting for applications in the nonlinear optics field. After a recording of high resolution X-ray diffraction data, we used Blessing formalism for the reduction and the processing of the raw data. Structure refinement was carried out by program SHELXL. The results of the refinement led to a reliability factor of about 6% at T = 293K and of 3% at T = 120K. The structure evolution study of lithium niobate with temperature made it possible to highlight the compound stability in the investigated temperature range. Results show a light displacement (about 0.01Å) of oxygen atoms around the Li - Nb bond.

A Yb3+-doped NaY(WO4)2crystal grown by the Czochralski technique

2008 ◽  
Vol 41 (3) ◽  
pp. 584-591 ◽  
Author(s):  
Jiandong Fan ◽  
Huaijin Zhang ◽  
Wentao Yu ◽  
Haohai Yu ◽  
Jiyang Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Refinement ◽  
Czochralski Method ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growth Habits ◽  
The Relationship

A transparent Yb3+:NaY(WO4)2single crystal with dimensions of 30 mm (diameter) × 40 mm has been grown by the Czochralski method. The high crystalline quality of the as-grown Yb3+:NaY(WO4)2crystals was confirmed by high-resolution X-ray diffraction. The effective segregation coefficients of elemental Yb, Na, Y and W in Yb3+:NaY(WO4)2were measured using the X-ray fluorescence method. Powder and single-crystal X-ray diffraction data of NaYb0.05Y0.95(WO4)2are reported. The structure refinement shows that NaYb0.05Y0.95(WO4)2crystallizes in the tetragonal space groupI41/a, witha=b= 5.2039 (2),c= 11.2838 (9) Å, α = β = γ = 90°,V= 305.57 (3) Å3andZ= 2. A series of possible growth faces (hkl) were determined from the crystal lattice and symmetry according to the Bravais–Friedel Donnay–Harker theory, and the relationship among crystal structure, growth habits and crystal morphology is discussed. In addition, the thermal properties of the crystal, including the specific heat, thermal expansion, thermal diffusion and thermal conductivity, were carefully investigated. The anisotropy of the crystal thermal conductivities is explained from the point of view of the crystal structure.

Structure refinement of Cu8GeS6 using X-ray diffraction data from a multiple-twinned crystal

1999 ◽  
Vol 55 (5) ◽  
pp. 721-725 ◽  
Author(s):  
Mitsuko Onoda ◽  
Xue-An Chen ◽  
Katsuo Kato ◽  
Akira Sato ◽  
Hiroaki Wada
Keyword(s):  
Diffraction Data ◽  
Room Temperature ◽  
Structure Refinement ◽  
Unit Cell ◽  
Temperature Phase ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Germanium Sulfide ◽  
Symmetry Operations

The structure of the orthorhombic room-temperature phase of Cu8GeS6 (copper germanium sulfide), Mr = 773.27, has been refined on the basis of X-ray diffraction data from a 12-fold twinned crystal applying a six-dimensional twin refinement technique. For 1804 unique reflections measured using Mo Kα radiation, RF was 0.083 with 77 structure parameters and 12 scale factors. The symmetry operations, the unit cell and other crystal data are (0, 0, 0; ½, ½, 0) + x, y, z; y, x, z; ¼ − x, ¾ − y, ½ + z; ¾ − y, ¼ − x, ½ + z; a = b = 9.9073 (3) Å, c = 9.8703 (4) Å, α = β = 90°, γ = 90.642 (4)°; V = 968.7 (1) Å3, Z = 4, Dx  = 5.358 Mg m−3, μ = 21.70 mm−1. The standard setting of the space group and the reduced unit cell are Pmn21; a = 7.0445 (3), b = 6.9661 (3), c = 9.8699 (5) Å; Z = 2.

STRUCTURE AND MAGNETIC PROPERTIES IN Mn-DOPED Si

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3469-3472 ◽  
Author(s):  
Z. Y. ZHAI ◽  
X. S. WU ◽  
W. ZHANG ◽  
B. QIAN ◽  
Y. M. ZHANG ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Magnetic Circular Dichroism ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Post Annealing ◽  
Two Phases ◽  
Mn Doped ◽  
Post Annealing Temperature

The composition of Mn 0.05 Si 0.95 polycrystalline films on (001) Si substrate are prepared by vacuum deposition and post-crystallization processes. X-ray diffraction studies indicate that there are two phases coexist in the film: tetragonal, Mn 4 Si 7 and diamond-like Si (Mn) . The content of Si(Mn) phase increases with increasing the post-annealing temperature. Temperature dependence of the magnetization shows that there are two ferromagnetic phases with Curie temperature of around 50 K and near room temperature, which is confirmed by x-ray magnetic circular dichroism (XMCD).

scholarly journals Generation of a Hetero Spin Complex from Iron(II) Iodide with Redox Active Acenaphthene-1,2-Diimine

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2998
Author(s):  
Dmitriy S. Yambulatov ◽  
Stanislav A. Nikolaevskii ◽  
Mikhail A. Kiskin ◽  
Kirill V. Kholin ◽  
Mikhail N. Khrizanforov ◽  
...  
Keyword(s):  
Room Temperature ◽  
Uv Spectroscopy ◽  
Magnetic Behavior ◽  
X Ray Diffraction ◽  
Iron Cation ◽  
X Ray ◽  
Redox Active ◽  
Anion Form ◽  
Ir And Uv Spectroscopy ◽  
Spin Complex

The reaction of the redox active 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) and iron(II) iodide in acetonitrile led to a new complex [(dpp-BIAN)FeIII2] (1). Molecular structure of 1 was determined by the single crystal X-ray diffraction analysis. The spin state of the iron cation in complex 1 at room temperature and the magnetic behavior of 1 in the temperature range of 2–300 K were studied using Mossbauer spectroscopy and magnetic susceptibility measurements, respectively. The neutral character of dpp-BIAN in 1 was confirmed by IR and UV spectroscopy. The electrochemistry of 1 was studied in solution and solid state using cyclic voltammetry. The generation of the radical anion form of the dpp-BIAN ligand upon reduction of 1 in a CH2Cl2 solution was monitored by EPR spectroscopy.

Structure determination of LiMoP2O7 from multiphase powder X-ray diffraction data

1990 ◽  
Vol 23 (6) ◽  
pp. 520-525 ◽  
Author(s):  
S. L. Wang ◽  
P. C. Wang ◽  
Y. P. Nieh
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Room Temperature ◽  
Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pattern Decomposition ◽  
Refinement Method ◽  
Final Agreement

The crystal structure of LiMoP2O7 was determined from conventional powder X-ray diffraction at room temperature in the presence of MoP2O7, MoO2 and Mo as impurities. Pattern decomposition was employed to eliminate complex contaminants prior to the Rietveld structure refinement. LiMoP2O7 crystallizes in the space group P21 with Z = 2, a = 4.8987 (3), b = 8.3912 (4), c = 7.0306 (4) Å, β = 109.327 (4)°, V = 272.71 Å3. Final agreement indicators were Rp = 0.0589, Rwp = 0.0772, RF = 0.054 and RI = 0.080. The framework of the structure consists of corner-sharing MoO6 octahedra and P2O7 groups, which form tunnels where the Li cations are located. The results give an example of analyzing a structure from a tetraphasic mixture using pattern decomposition in conjunction with the Rietveld refinement method.

The α-phase of SrTeO3 at 295 K

2007 ◽  
Vol 63 (3) ◽  
pp. i75-i76 ◽  
Author(s):  
Valery E. Zavodnik ◽  
Sergey A. Ivanov ◽  
Adam I. Stash
Keyword(s):  
Room Temperature ◽  
Second Harmonic ◽  
Czochralski Method ◽  
Structure Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Α Phase ◽  
Oxygen Anions ◽  
Generation Test ◽  
Selection Of

The crystal structure of strontium tellurite (STO), SrTeO3, has been determined at room temperature using X-ray diffraction data obtained from single crystals grown by the Czochralski method. Selection of a non-centrosymmetric (C2) structure model was confirmed by the second harmonic generation test. The structure of STO is built up of three types of distorted [SrO x ] polyhedra (x = 6, 7 and 8) which share their oxygen anions with TeO3 pyramidal units. These main anionic polyhedra are responsible for establishing two types of tunnels required for the electron lone pairs of the Te4+ cation.

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