Influence of high pressure on the fluctuation conductivity of YBa2Cu3O7−δ single crystals with an oxygen deficiency

2006 ◽  
Vol 32 (6) ◽  
pp. 614-616 ◽  
Author(s):  
M. A. Obolenskii ◽  
R. V. Vovk ◽  
A. V. Bondarenko
Keyword(s):  
High Pressure ◽  
Single Crystals ◽  
Oxygen Deficiency ◽  
Fluctuation Conductivity

scholarly journals Composition variation and electron irradiation effects on the fluctuation conductivity in Y1–zPrzBa2Cu3O7−δ single crystals

2020 ◽  
Vol 31 (21) ◽  
pp. 19429-19436
Author(s):  
A. Chroneos ◽  
D. D. Kolesnikov ◽  
I. A. Taranova ◽  
A. V. Matsepulin ◽  
R. V. Vovk
Keyword(s):  
Single Crystals ◽  
Oxygen Deficiency ◽  
High Energy ◽  
Superconducting Transition ◽  
Crossover Point ◽  
Fluctuation Conductivity ◽  
High Energy Electrons ◽  
Composition Variation ◽  
Temperature Dependences ◽  
Different Temperatures

AbstractA comparative analysis of the changes in the fluctuation conductivity and characteristics of the superconducting state of YBa2Cu3O7–δ single crystals caused by various types of defects is carried out. These defects appeared due to irradiation with high-energy electrons (radiation doses from 1.4 to 8.8 1018 cm–2), changes in oxygen deficiency (0.08 ≤ δ ≤ 0.23) due to annealing at different temperatures, or doping with praseodymium (Y1–zPrzBa2Cu3O7−δ, 0 ≤ z ≤ 0.5 at optimal oxygen concentration). It is shown that the introduction of such defects leads to a significant expansion of the temperature range of the existence of excess conductivity, and upon doping with praseodymium, it also leads to the appearance of a thermally activated deflection on the temperature dependence of the electrical resistance. The effect of such defects on the superconducting transition temperature, Tc, and the coherence length along the c axis, ξc(0), is studied. In particular, ξc(0) more than quadruples (at z = 0.43), while the 2D-3D crossover point shifts towards higher temperatures. Possible reasons for the suppression of superconductivity in YBa2Cu3O7–δ upon irradiation with fast electrons and the qualitatively different temperature dependences of its resistivity in the basal plane, ρab (T), are discussed.

Effect of high pressure on the fluctuation conductivity and the charge transfer of YBa2Cu3O7−δ single crystals

2008 ◽  
Vol 453 (1-2) ◽  
pp. 69-74 ◽  
Author(s):  
R.V. Vovk ◽  
M.A. Obolenskii ◽  
A.A. Zavgorodniy ◽  
A.V. Bondarenko ◽  
I.L. Goulatis ◽  
...  
Keyword(s):  
High Pressure ◽  
Charge Transfer ◽  
Single Crystals ◽  
Fluctuation Conductivity

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

Femtosecond pump-probe characterization of high-pressure grown Al x Ga 1-x N single crystals

2009 ◽  
Author(s):  
Jie Zhang ◽  
A. Belousov ◽  
S. Katrych ◽  
J. Jun ◽  
J. Karpinski ◽  
...  
Keyword(s):  
High Pressure ◽  
Single Crystals ◽  
Pump Probe

Crystal Field Analysis of the Magnetization Curves of HoFe11Ti under High Pressure

2013 ◽  
Vol 818 ◽  
pp. 72-76 ◽  
Author(s):  
Gang Su
Keyword(s):  
High Pressure ◽  
Hydrogen Atom ◽  
Electric Field ◽  
Single Crystals ◽  
High Pressures ◽  
Field Analysis ◽  
Magnetization Curves ◽  
Crystalline Electric Field ◽  
Crystalline Anisotropy ◽  
Magneto Crystalline Anisotropy

The crystalline electric field parameters Anmfor HoFe11Ti under different pressures were evaluated by fitting calculations to the magnetization curves measured on the single crystals at several temperatures. It was found that magneto-crystalline anisotropy has been changed by high pressure and the Anmfor HoFe11Ti under high pressures are strikingly different from Anmfor the corresponding HoFe11Ti H with interstitial hydrogen atom.

Ultraviolet light emission from self-organized p–n domains in cubic boron nitride bulk single crystals grown under high pressure

2002 ◽  
Vol 81 (22) ◽  
pp. 4145-4147 ◽  
Author(s):  
T. Taniguchi ◽  
K. Watanabe ◽  
S. Koizumi ◽  
I. Sakaguchi ◽  
T. Sekiguchi ◽  
...  
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Single Crystals ◽  
Ultraviolet Light ◽  
Light Emission ◽  
Cubic Boron Nitride ◽  
Self Organized ◽  
Bulk Single Crystals

High-pressure phase transformation of oriented CdSb single crystals

2005 ◽  
Vol 41 (3) ◽  
pp. 217-219 ◽  
Author(s):  
A. Yu. Mollaev ◽  
R. K. Arslanov ◽  
R. G. Dzhamamedov ◽  
S. F. Marenkin ◽  
S. A. Varnavskii
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Single Crystals ◽  
High Pressure Phase ◽  
Pressure Phase

scholarly journals Vibrational anisotropy of <i>δ</i>-(Al,Fe)OOH single crystals as probed by nuclear resonant inelastic X-ray scattering

2021 ◽  
Vol 33 (4) ◽  
pp. 485-502
Author(s):  
Johannes Buchen ◽  
Wolfgang Sturhahn ◽  
Takayuki Ishii ◽  
Jennifer M. Jackson
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystals ◽  
Vibrational Properties ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
X Ray ◽  
X Ray Scattering ◽  
The Mean ◽  
Vibrational Anisotropy

Abstract. The formation of high-pressure oxyhydroxide phases spanned by the components AlOOH–FeOOH–MgSiO2(OH)2 in experiments suggests their capability to retain hydrogen in Earth's lower mantle. Understanding the vibrational properties of high-pressure phases provides the basis for assessing their thermal properties, which are required to compute phase diagrams and physical properties. Vibrational properties can be highly anisotropic, in particular for materials with crystal structures of low symmetry that contain directed structural groups or components. We used nuclear resonant inelastic X-ray scattering (NRIXS) to probe lattice vibrations that involve motions of 57Fe atoms in δ-(Al0.87Fe0.13)OOH single crystals. From the recorded single-crystal NRIXS spectra, we calculated projections of the partial phonon density of states along different crystallographic directions. To describe the anisotropy of central vibrational properties, we define and derive tensors for the partial phonon density of states, the Lamb–Mössbauer factor, the mean kinetic energy per vibrational mode, and the mean force constant of 57Fe atoms. We further show how the anisotropy of the Lamb–Mössbauer factor can be translated into anisotropic displacement parameters for 57Fe atoms and relate our findings on vibrational anisotropy to the crystal structure of δ-(Al,Fe)OOH. As a potential application of single-crystal NRIXS at high pressures, we discuss the evaluation of anisotropic thermal stresses in the context of elastic geobarometry for mineral inclusions. Our results on single crystals of δ-(Al,Fe)OOH demonstrate the sensitivity of NRIXS to vibrational anisotropy and provide an in-depth description of the vibrational behavior of Fe3+ cations in a crystal structure that may motivate future applications of NRIXS to study anisotropic vibrational properties of minerals.

scholarly journals Ge0.57Ti0.43O2: a new high-pressure material with rutile-type crystal structure

2018 ◽  
Vol 74 (7) ◽  
pp. 1010-1012 ◽  
Author(s):  
Emil Stoyanov ◽  
Kurt Leinenweber ◽  
Thomas L. Groy ◽  
Abds-Sami Malik
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
High Pressure ◽  
Single Crystals ◽  
Structure Type ◽  
Site Symmetry ◽  
Rutile Structure ◽  
High Pressure And Temperature ◽  
Atom Position ◽  
Type Crystal

Single crystals of a GeO2–TiO2 solid solution with the corresponding composition Ge0.57Ti0.43O2 (germanium titanium tetraoxide) were obtained by devitrification of germania-titania glass at high pressure and temperature. The new compound crystallizes in the rutile structure type (space group P42/mnm), where Ge and Ti share the same position M (site symmetry m.mm), with occupancy values of 0.57 (3) and 0.43 (3), respectively, and one O-atom position (m.2m). The M site is in a sixfold O-atom coordination and, as in the original TiO2 rutile structure, an elongation of the O—M—O bonds along the c-axis direction of the coordination polyhedron and deviation of the angles from 90° lead to a decrease in the coordination symmetry from octahedral to tetragonal. The Ge and Ti atoms are fully disordered in the structure, which indicates that the rutile structure is surprisingly pliant given the differing sizes of the two cations.

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