Pt–Cu2O–Cu double injection diodes

We report here on recent measurements made on our Pt–Cu2O–Cu diodes, annealed at an air pressure of 1 to 2 Torr, which we interpret as due to double injection, i.e. injection of holes from the platinum electrode and injection of electrons from the copper–Cu2O junction into the single crystal Cu2O region. The measurements discussed here include the forward I–V characteristics at various temperatures, current vs. thickness relationship at constant voltage, the effect of photo-memory on the I–V characteristics, and the discovery of a negative resistance regime at below room temperature at sufficiently high injection levels. The analysis of the temperature dependence of the current in the ohmic and the [Formula: see text] regimes, together with the effect of photomemory on the I–V characteristics enable us to identify the [Formula: see text] regime as the Ashley–Milnes regime with field dependent mobility.

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Температурная зависимость напряжения, вызванного спиновым током в гетероструктуре манганит/иридат

Физика твердого тела ◽

10.21883/ftt.2021.09.51259.26h ◽

2021 ◽

Vol 63 (9) ◽

pp. 1321

Author(s):

Т.А. Шайхулов ◽

К.Л. Станкевич ◽

К.И. Константинян ◽

В.В. Демидов ◽

Г.А. Овсянников

Keyword(s):

Thin Film ◽

Single Crystal ◽

Temperature Dependence ◽

Hall Effect ◽

Ferromagnetic Resonance ◽

Room Temperature ◽

Ferromagnetic Layer ◽

Spin Current ◽

Epitaxial Thin Film ◽

Inverse Spin Hall Effect

The temperature dependence of the voltage induced by the spin current was studied in an epitaxial thin-film La0.7Sr0.3MnO3 / SrIrO3 heterostructure deposited on a single-crystal NdGaO3 substrate. The spin current was generated by microwave pumping under conditions of ferromagnetic resonance in the La0.7Sr0.3MnO3 ferromagnetic layer and was detected in the SrIrO3 layer due to inverse spin Hall effect. A significant increase of half-width of the spin current spectrum along with the rise of amplitude of the spin current upon cooling from room temperature (300 K) to 135 K were observed.

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Crystal Distortions Associated with Magnetic Ordering in the Antiferromagnetic Compound VF2

Advances in X-ray Analysis ◽

10.1154/s0376030800008533 ◽

1970 ◽

Vol 14 ◽

pp. 433-440

Author(s):

W. S. McCain ◽

D. L. Albright ◽

W. O. J. Boo

Keyword(s):

Single Crystal ◽

Temperature Dependence ◽

Room Temperature ◽

Magnetic Ordering ◽

The Body ◽

The Other ◽

Magnetic Interactions ◽

One Dimensional ◽

Lattice Constants ◽

Vanadium Ions

AbstractLattice constants were measured as a function of temperature by single crystal diffracrometry in the temperature range which includes the Néel temperature of VF2(TN= 7°K). The lattice constants of VF2(D4h14=P42m n m) were measured from room temperature down to 4.2°K. In this range rhe tetragonal c-axis contracts 0.58% from 3.2359 Å (RT) to 3.2170 Å (4.2°K). On the other hand, the a-axes show a net expansion of 0.18% from 4.8023 Å (RT) to 4.8110 Å at 4.2°K. The temperature dependence of the lattice constants can be correlated with anisotropy of exchange forces. Vanadium Ions occupy the center and corner positions of the unit cell. Strong magnetic interactions are directed parallel to the c-axis >001< with considerably weaker interactions parallel to the body diagonals >111< The relative strengths of the two exchange integrals are J >001< = 50 J >111<. As a consequence the magnetic ordering is one-dîmensional along the c-axis and the associated distortions arise from the strong magnetic interactions along this axis.

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Temperature dependence of the AV3O7 (A = Ca, Sr) structure

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768107050550 ◽

2007 ◽

Vol 63 (6) ◽

pp. 836-842 ◽

Cited By ~ 1

Author(s):

Sebastian Prinz ◽

Karine M. Sparta ◽

Georg Roth

Keyword(s):

Single Crystal ◽

Temperature Dependence ◽

Crystal Structures ◽

Room Temperature ◽

X Ray Diffraction ◽

X Ray ◽

Space Groups ◽

Temperature Ranges ◽

First Time

The V4+ (spin ½) oxovanadates AV3O7 (A = Ca, Sr) were synthesized and studied by means of single-crystal X-ray diffraction. The room-temperature structures of both compounds are orthorhombic and their respective space groups are Pnma and Pmmn. The previously assumed structure of SrV3O7 has been revised and the temperature dependence of both crystal structures in the temperature ranges 297–100 K and 315–100 K, respectively, is discussed for the first time.

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Transport Studies in Single-Crystal Films of Cosi2 and Nisi2

MRS Proceedings ◽

10.1557/proc-25-575 ◽

1983 ◽

Vol 25 ◽

Cited By ~ 4

Author(s):

J. C. Hensel ◽

R. T. Tung ◽

J. M. Poate ◽

F. C. Unterwald ◽

D. C. Jacobson

Keyword(s):

Thin Films ◽

Single Crystal ◽

Temperature Dependence ◽

Room Temperature ◽

Room Temperature Resistivity ◽

Transport Studies ◽

Single Crystal Films ◽

Crystal Films ◽

The Difference ◽

Temperature Resistivity

ABSTRACTTransport studies have been performed on thin films of CoSi 2 and NiSis2 in the temperature range 1 to 300 K. The conductivities are metallic with essentially the same temperature dependence; however, the residual resistivities are markedly different even though the two silicides are structurally similar (the room temperature resistivity of NiSi2 being at least twice that of CoSi2 of 15 μΩ cm). The difference is attributed to intrinsic defects in NiSi2. This defect has been simulated by ion bombardment of the film where it is also shown that Matthiesen's rule is obeyed over a remarkable range of bombardment doses.

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Dielectric Constant of Barium Titanate Synthesized by Containerless Processing

MRS Proceedings ◽

10.1557/proc-848-ff10.4 ◽

2004 ◽

Vol 848 ◽

Author(s):

Jianding Yu ◽

Paul-François Paradis ◽

Takehiko Ishikawa ◽

Shinichi Yoda

Keyword(s):

Dielectric Constant ◽

Barium Titanate ◽

Single Crystal ◽

Temperature Dependence ◽

Room Temperature ◽

Undercooled Liquid ◽

Electrostatic Levitation ◽

Containerless Processing ◽

Synthesis Technique ◽

Loss Component

ABSTRACTContainerless processing is an attractive synthesis technique that permits deep undercooling and provides the possibility to solidify the undercooled liquid into a selected phase, and to synthesize materials with novel properties. Spheroidal BaTiO3 samples with a diameter of approximately 2mm were solidified by containerless processing, using an electrostatic levitation apparatus. Single crystal hexagonal BaTiO3 and polycrystalline perovskite BaTiO3 were successfully synthesized at different undercoolings levels. An oxygen-deficient single crystal of hexagonal BaTiO3 obtained with this method, exhibited a giant permittivity higher than 100000, with a loss component tanδ of about 0.1 at room temperature. The permittivity showed weak temperature dependence in the 70 K to 300 K range, and a dramatic drop by 2 orders of magnitude below 70 K. In comparison, the polycrystalline perovskite BaTiO3 showed a permittivity of 4000 at room temperature.

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Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009292x ◽

1976 ◽

Vol 34 ◽

pp. 592-593

Author(s):

Ernest L. Hall ◽

J. B. Vander Sande

Keyword(s):

Mechanical Properties ◽

Single Crystal ◽

Dislocation Structure ◽

Room Temperature ◽

Elevated Temperatures ◽

Strain Curve ◽

Optical Devices ◽

Semiconductor Compound ◽

Wide Range ◽

Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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X-ray dislocation substructure observations and strengthening mechanisms in α-iron single crystal between room temperature and 123 K

Journal de Physique ◽

10.1051/jphys:01974003507-8055700 ◽

1974 ◽

Vol 35 (7-8) ◽

pp. 557-569 ◽

Cited By ~ 11

Author(s):

G. Coulon ◽

J. Lecoq ◽

B. Escaig

Keyword(s):

Single Crystal ◽

Room Temperature ◽

Dislocation Substructure ◽

Strengthening Mechanisms ◽

X Ray ◽

Iron Single Crystal

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ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

Alternative Energy and Ecology (ISJAEE) ◽

10.15518/isjaee.2019.01-03.056-066 ◽

2019 ◽

pp. 56-66

Author(s):

I. Khidirov ◽

V. V. Getmanskiy ◽

A. S. Parpiev ◽

Sh. A. Makhmudov

Keyword(s):

Heat Capacity ◽

High Temperature ◽

Titanium Carbide ◽

Temperature Dependence ◽

Carbon Concentration ◽

Room Temperature ◽

Thermodynamic Characteristics ◽

Liquid Nitrogen Temperature ◽

Analysis Data ◽

Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

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Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

10.26434/chemrxiv.11345063.v2 ◽

2020 ◽

Author(s):

Keishiro Yamashita ◽

Kazuki Komatsu ◽

Hiroyuki Kagi

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Crystal Growth ◽

Single Crystal ◽

Room Temperature ◽

Growth Technique ◽

Salt Hydrate ◽

X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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