Synthesis, characterization and wide range frequency and temperature dependent electrical modulus study of LaCrO3 and cobalt (Co) doped LaCrO3 perovskite compounds

Multifunctional luminescent materials of six Ln-MOFs have been designed and synthesized by the co-doping strategy. Thus a wide range of light emitting spectra and different temperature-dependent luminescence behavior were displayed.

Download Full-text

On the examination of temperature-dependent possible current-conduction mechanisms of Au/(nanocarbon-PVP)/n-Si Schottky barrier diodes in wide range of voltage

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-021-05669-0 ◽

2021 ◽

Author(s):

Ömer Sevgili

Keyword(s):

Schottky Barrier ◽

Schottky Barrier Diodes ◽

Temperature Dependent ◽

Conduction Mechanisms ◽

Wide Range ◽

Current Conduction

Download Full-text

Study and Assessment of Defect and Trap Effects on the Current Capabilities of a 4H-SiC-Based Power MOSFET

Electronics ◽

10.3390/electronics10060735 ◽

2021 ◽

Vol 10 (6) ◽

pp. 735

Author(s):

Fortunato Pezzimenti ◽

Hichem Bencherif ◽

Giuseppe De Martino ◽

Lakhdar Dehimi ◽

Riccardo Carotenuto ◽

...

Keyword(s):

Drain Current ◽

Oxide Semiconductor ◽

Temperature Dependent ◽

Channel Mobility ◽

Blocking Voltage ◽

Current Voltage ◽

Wide Range ◽

Temperature Ranges ◽

Joint Contribution ◽

State Resistance

A numerical simulation study accounting for trap and defect effects on the current-voltage characteristics of a 4H-SiC-based power metal-oxide-semiconductor field effect transistor (MOSFET) is performed in a wide range of temperatures and bias conditions. In particular, the most penalizing native defects in the starting substrate (i.e., EH6/7 and Z1/2) as well as the fixed oxide trap concentration and the density of states (DoS) at the 4H-SiC/SiO2 interface are carefully taken into account. The temperature-dependent physics of the interface traps are considered in detail. Scattering phenomena related to the joint contribution of defects and traps shift the MOSFET threshold voltage, reduce the channel mobility, and penalize the device current capabilities. However, while the MOSFET on-state resistance (RON) tends to increase with scattering centers, the sensitivity of the drain current to the temperature decreases especially when the device is operating at a high gate voltage (VGS). Assuming the temperature ranges from 300 K to 573 K, RON is about 2.5 MΩ·µm2 for VGS > 16 V with a percentage variation ΔRON lower than 20%. The device is rated to perform a blocking voltage of 650 V.

Download Full-text

Hydrogenation of methylacetylene. III. The reaction of methylacetylene with hydrogen catalyzed by nickel, copper, and their alloys

Canadian Journal of Chemistry ◽

10.1139/v68-101 ◽

1968 ◽

Vol 46 (4) ◽

pp. 623-633 ◽

Cited By ~ 12

Author(s):

R. S. Mann ◽

K. C. Khulbe

Keyword(s):

Activation Energy ◽

Nickel Catalyst ◽

Hydrogen Pressure ◽

Constant Volume ◽

Temperature Dependent ◽

Nickel Copper ◽

Wide Range ◽

Initial Hydrogen Pressure

The reaction between methylacetylene and hydrogen over unsupported nickel, copper, and their alloys has been investigated in a static constant volume system between 20 and 220 °C for a wide range of reactant ratios. The order of reaction with respect to hydrogen was one and nearly independent of temperature. While the order of reaction with respect to methylacetylene over nickel catalyst was slightly negative and temperature dependent, it was always positive and nearly independent of temperature for copper and copper-rich alloys. Selectivity was independent of initial hydrogen pressure for nickel and copper only; for others it decreased rapidly with increasing hydrogen pressure. The overall activation energy varied between 9 and 21.2 kcal/g mole. Selectivity and extent of polymerization increased with increasing amount of copper in the alloy.

Download Full-text

Magnetic properties of undoped and Co-doped n-type β–FeSi2.5 single crystals

Journal of Materials Research ◽

10.1557/jmr.2002.0429 ◽

2002 ◽

Vol 17 (11) ◽

pp. 2960-2965 ◽

Cited By ~ 4

Author(s):

E. Arushanov ◽

L. Ivanenko ◽

D. Eckert ◽

G. Behr ◽

U. K. Rößler ◽

...

Keyword(s):

Activation Energy ◽

Magnetic Properties ◽

Magnetic Susceptibility ◽

External Field ◽

Single Crystals ◽

Spin Glasses ◽

Paramagnetic Centers ◽

Temperature Dependent ◽

Paramagnetic Curie Temperature ◽

Co Doped

Results of magnetization and magnetic susceptibility measurements on undoped and Co-doped FeSi2.5 single crystals are presented. The temperature dependence of the magnetic susceptibility of the Co-doped sample in the range of 5–300 K can be explained by temperature-dependent contributions due to paramagnetic centers and the carriers excited thermally in the extrinsic conductivity region. The values of the paramagnetic Curie temperature and activation energy of the donor levels were estimated. It is also shown that the magnetic susceptibility of Co-doped samples cooled in zero external field and in a field are different. This resembles the properties of spin-glasses and indicates the presence of coupling between magnetic centers.

Download Full-text

Effect of Sintering Temperature on Metal-Insulator Phase Transition in La1-xCaxMnO3 Perovskites

Frontiers in Advanced Materials Research ◽

10.34256/famr2014 ◽

2020 ◽

Vol 2 (1) ◽

pp. 37-42

Author(s):

Arunachalam M ◽

Thamilmaran P ◽

Sakthipandi K

Keyword(s):

Phase Transition ◽

Bulk Modulus ◽

Sintering Temperature ◽

Magnetic Sensors ◽

Temperature Dependent ◽

Metal Insulator ◽

Wide Range ◽

Different Temperatures ◽

Insulator Phase Transition

Lanthanum calcium based perovskites are found to be advantageous for the possible applications in magnetic sensors/reading heads, cathodes in solid oxide fuel cells, and frequency switching devices. In the present investigation La0.3Ca0.7MnO3 perovskites were synthesised through solid state reaction and sintered at four different temperatures such as 900, 1000, 1100 and 1200˚ C. X-ray powder diffraction pattern confirms that the prepared La0.3Ca0.7MnO3 perovskites have orthorhombic structure with Pnma space group. Ultrasonic in-situ measurements have been carried out on the La0.3Ca0.7MnO3 perovskites over wide range of temperature and elastic constants such as bulk modulus of the prepared La0.3Ca0.7MnO3 perovskites was obtained as function of temperature. The temperature-dependent bulk modulus has shown an interesting anomaly at the metal-insulator phase transition. The metal insulator transition temperature derived from temperature-dependent bulk modulus increases from temperature 352˚ C to 367˚ C with the increase of sintering temperature from 900 to 1200˚ C.

Download Full-text

Resurrecting low-mass axion dark matter via a dynamical QCD scale

Journal of High Energy Physics ◽

10.1007/jhep12(2021)216 ◽

2021 ◽

Vol 2021 (12) ◽

Author(s):

Lucien Heurtier ◽

Fei Huang ◽

Tim M.P. Tait

Keyword(s):

Dark Matter ◽

Standard Model ◽

Temperature Dependent ◽

Axion Field ◽

Wide Range ◽

The Standard Model ◽

Low Mass ◽

Higher Temperature ◽

Relic Abundance ◽

Dependent Mass

Abstract In the framework where the strong coupling is dynamical, the QCD sector may confine at a much higher temperature than it would in the Standard Model, and the temperature-dependent mass of the QCD axion evolves in a non-trivial way. We find that, depending on the evolution of ΛQCD, the axion field may undergo multiple distinct phases of damping and oscillation leading generically to a suppression of its relic abundance. Such a suppression could therefore open up a wide range of parameter space, resurrecting in particular axion dark-matter models with a large Peccei-Quinn scale fa ≫ 1012 GeV, i.e., with a lighter mass than the standard QCD axion.

Download Full-text

A Temperature Dependent, Single Particle, Lithium Ion Cell Model Including Electrolyte Diffusion

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4028154 ◽

2014 ◽

Vol 137 (1) ◽

Cited By ~ 54

Author(s):

Tanvir R. Tanim ◽

Christopher D. Rahn ◽

Chao-Yang Wang

Keyword(s):

Single Particle ◽

Lithium Ion ◽

Particle Model ◽

Voltage Response ◽

Model Parameters ◽

Battery Management System ◽

Temperature Dependent ◽

Lithium Ion Cell ◽

Pulse Charge ◽

Wide Range

Low-order, explicit models of lithium ion cells are critical for real-time battery management system (BMS) applications. This paper presents a seventh-order, electrolyte enhanced single particle model (ESPM) with electrolyte diffusion and temperature dependent parameters (ESPM-T). The impedance transfer function coefficients are explicit in terms of the model parameters, simplifying the implementation of temperature dependence. The ESPM-T model is compared with a commercially available finite volume based model and results show accurate matching of pulse responses over a wide range of temperature (T) and C-rates (I). The voltage response to 30 s pulse charge–discharge current inputs is within 5% of the commercial code for 25 °C<T<50 °C at I≤12.5C and -10 °C<T<50°C at I≤1C for a graphite/nickel cobalt manganese (NCM) lithium ion cell.

Download Full-text