THE STRUCTURE AND TRANSPORT PROPERTIES OF La0.9Sr0.1MnO3

2007 ◽  
Vol 14 (04) ◽  
pp. 813-816 ◽  
Author(s):  
Z. LUO ◽  
J. GAO
Keyword(s):  
Oxygen Content ◽  
Oxygen Deficiency ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Pressures ◽  
Out Of Plane ◽  
Different Temperatures ◽  
Small Polarons ◽  
Temperature Resistivity

Thin films of La 0.9 Sr 0.1 MnO 3 (LSMO) were grown on SrTiO 3 substrate by pulsed laser deposition technique at different temperatures and with various oxygen partial pressures. X-ray diffraction spectra confirmed that the grown films are of single phase. The influence of oxygen deficiency on the structure of these grown films has been studied. X-ray diffraction data suggested that higher oxygen content generally results in smaller out-of- plane lattice parameters and annealing in oxygen may further decrease the lattice parameters. The 2-θ value increases with oxygen pressure. Typically, the oxygen-deficient films behave like semiconductors. For films grown at the same temperature, the conductivity is enhanced if the oxygen content is increased. Those films grown in 1 mbar oxygen partial pressure show an upturn at low temperature. Resistivity is dominated by the hopping of adiabatic small polarons at high temperature.

CHANGES IN PHYSICAL PROPERTIES OF THE HIGH-Tc SUPERCONDUCTOR Y-Ba-Cu-O DUE TO Cu DEFICIENCY

1989 ◽  
Vol 03 (06) ◽  
pp. 499-503 ◽  
Author(s):  
Y.D. YAO ◽  
Y.H. KAO ◽  
J.J. SIMMINS ◽  
R.L. SNYDER ◽  
Z. TAO ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Room Temperature ◽  
Single Phase ◽  
Nonlinear Dependence ◽  
Room Temperature Resistivity ◽  
X Ray Diffraction ◽  
High Tc ◽  
X Ray ◽  
Cu Deficiency ◽  
Temperature Resistivity

Stoichiometry of the well-known high-T c compound YBa 2 Cu 3 O y is modified by varying the Cu concentration in the system, and changes in the oxygen content and superconducting properties are investigated. The oxygen content shows a nonlinear dependence on the Cu concentration. For Cu deficiency up to 20%, the transition temperature T c remains at a nearly constant value of 93 K. X-ray diffraction measurements show that the compound is orthorhombic in this range of stoichiometric variation, and the Cu -deficient superconductor is single phase. The room temperature resistivity increases exponentially while the critical current density decreases exponentially with increasing Cu deficiency. These results indicate that the predominant mechanism for high-T c superconductivity is closely related to the local structure around the Cu and O atoms.

Influence of oxygen deficiency on the out-of-plane tilt of epitaxial Y2O3 films on Ni–5%W tapes

2009 ◽  
Vol 24 (2) ◽  
pp. 520-525 ◽  
Author(s):  
C. Cantoni ◽  
E.D. Specht ◽  
A. Goyal ◽  
X. Li ◽  
M. Rupich
Keyword(s):  
Electron Microscopy ◽  
Oxygen Vacancies ◽  
Oxygen Deficiency ◽  
Oxygen Stoichiometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Substrate Interface ◽  
Transmission Electron ◽  
Out Of Plane ◽  
Film Substrate

We analyzed the crystallographic c-axis tilt of (001) Y2O3 films grown on biaxially textured Ni–5%W tapes under different oxygen flux conditions. Results show that different tilting mechanisms were effective in films with different oxygen stoichiometry. Moreover, the structure of the film/substrate interface investigated by transmission electron microscopy, and the residual strain of the film investigated by x-ray diffraction were also dependent on the film oxygen content. Although the oxygen stoichiometric Y2O3 sample exhibited a coherent film/substrate interface and the sharpest out-of-plane texture, the films grown under reduced oxygen pressure exhibited a smaller overall c-axis tilt due to formation of interface dislocations and regions in which the film oxygen vacancies ordered to form a lattice superstructure.

scholarly journals A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu
Keyword(s):  
Stearic Acid ◽  
Antibacterial Properties ◽  
Alkali Resistance ◽  
Poplar Wood ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Acid And Alkali Resistance ◽  
The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

scholarly journals Hydrothermal Ageing and Its Effect on Fracture Load of Zirconia Dental Implants

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3103
Author(s):  
Laurent Gremillard ◽  
Agnès Mattlet ◽  
Alexandre Mathevon ◽  
Damien Fabrègue ◽  
Bruno Zberg ◽  
...  
Keyword(s):  
Dental Implants ◽  
Fracture Load ◽  
Accelerated Ageing ◽  
Dental Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dental Restorations ◽  
Different Temperatures ◽  
Mechanical Performances ◽  
Kinetics Of

Due to growing demand for metal-free dental restorations, dental ceramics, especially dental zirconia, represent an increasing share of the dental implants market. They may offer mechanical performances of the same range as titanium ones. However, their use is still restricted by a lack of confidence in their durability and, in particular, in their ability to resist hydrothermal ageing. In the present study, the ageing kinetics of commercial zirconia dental implants are characterized by X-ray diffraction after accelerated ageing in an autoclave at different temperatures, enabling their extrapolation to body temperature. Measurements of the fracture loads show no effect of hydrothermal ageing even after ageing treatments simulated a 90-year implantation.

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

scholarly journals Modeling of magneto-conductivity of bismuth selenide: a topological insulator

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Field Range ◽  
X Ray ◽  
Bulk Carriers ◽  
Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

scholarly journals β-Y(BO2)3 – a new member of the β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu) structure family

2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).

Structural Properties Of Co/Re Superlattices

1991 ◽  
Vol 238 ◽  
Author(s):  
Y. Huai ◽  
R. W. Cochrane ◽  
Y. Shi ◽  
H. E. Fischer ◽  
M. Sutton
Keyword(s):  
Structural Disorder ◽  
Multilayer Films ◽  
Film Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bilayer Films ◽  
Out Of Plane ◽  
Reflectivity Data ◽  
Sharp Interfaces ◽  
Good Agreement

ABSTRACTThe structures of equal-thickness Co/Re multilayer films and several Co/Re bilayer films have been investigated by X-ray diffraction at low and high angles. Analysis of low-angle reflectivity data from bilayer films indicates that interfacial intermixing is limited to three monolayers and that the two interfacial configurations are different. The high-angle X-ray diffraction data show that multilayer films have coherent interfaces and a highly textured structure with hep [002] orientations normal to the film plane for periods 21 Å ≤ Λ ≤220 Å. Detailed structures have been determined by fitting the X-ray spectra to calculated ones using a trapezoidal model. The results indicate that samples with 42 Å≤ Λ ≤220 Å have relatively sharp interfaces, in good agreement with the bilayer results. In addition, an out-of-plane expansion of the Co (002) layer is observed in samples with large Λ and results from structural disorder leading to a reduced atomic density. For Λ <21 Å the interfaces arise from the rougher surfaces of the deposited layers.

Superstructure formation in the solid solution Sc3Pt3−xIn3 (x = 0–0.93)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nataliya L. Gulay ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Stefan Seidel ◽  
...  
Keyword(s):  
Solid Solution ◽  
Diffraction Data ◽  
High Frequency ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Platinum Content ◽  
Arc Melting ◽  
Modulation Vector

Abstract The equiatomic indide ScPtIn (ZrNiAl type, space group P 6 ‾ $&#x203e;{6}$ 2m) shows an extended solid solution Sc3Pt3–xIn3. Several samples of the Sc3Pt3–xIn3 series were synthesized from the elements by arc-melting and subsequent annealing, or directly in a high frequency furnace. The lowest platinum content was observed for Sc3Pt2.072(3)In3. All samples were characterized by powder X-ray diffraction and their lattice parameters and several single crystals were studied on the basis of precise single crystal X-ray diffractometer data. The correct platinum occupancy parameters were refined from the diffraction data. Decreasing platinum content leads to decreasing a and c lattice parameters. Satellite reflections were observed for the Sc3Pt3–xIn3 crystals with x = 0.31–0.83. These satellite reflections could be described with a modulation vector ( 1 3 , 1 3 , γ ) $\left(\frac{1}{3},\frac{1}{3},\gamma \right)$ ( γ = 1 2 $\gamma =\frac{1}{2}$ c* for all crystals) and are compatible with trigonal symmetry. The interplay of platinum filled vs. empty In6 trigonal prisms is discussed for an approximant structure with space group P3m1.

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