Determination of the Purity of Metals by Temperature-Dependent Electrical Properties

2008 ◽  
pp. 75-75-15
Author(s):  
DD Pollock
Keyword(s):  
Electrical Properties ◽  
Temperature Dependent

Temperature Dependent Hall Measurements on CdGeAs2

1999 ◽  
Vol 607 ◽  
Author(s):  
A.J. Ptak ◽  
S. Jain ◽  
K.T Stevens ◽  
T.H. Myers ◽  
P.G. Schunemann ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Shallow Donor ◽  
Temperature Dependent ◽  
Out Of Plane ◽  
Background Doping ◽  
Apparent Variation ◽  
P Type ◽  
Matched Samples ◽  
Residual Growth

AbstractSeventeen samples of CdGeAs2 have been extensively characterized by temperature-dependent Hall effect and resistivity measurements. Due to the anisotropic nature of the electrical properties, carefully matched sample sets were fabricated with the c-axis either in or out of the plane of the sample. The matched samples allowed determination of carrier concentration and both in-plane and out-of-plane mobilities as a function of temperature. The electrical properties of both undoped and lightly doped samples were dominated by either native defects or residual growth impurities, leading to compensated p-type material. N-type doped material was obtained only with heavy doping. An apparent variation in acceptor activation energy between 110 and 165 meV could be best explained in terms of two deep acceptor levels and at least one shallow donor. Room temperature absorption coefficient data and the relation to background doping is also reported.

scholarly journals Temperature Dependence of G and D’ Phonons in Monolayer to Few-Layer Graphene with Vacancies

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Mingming Yang ◽  
Longlong Wang ◽  
Xiaofen Qiao ◽  
Yi Liu ◽  
Yufan Liu ◽  
...  
Keyword(s):  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Intrinsic Properties ◽  
Temperature Dependent ◽  
Phonon Interaction ◽  
Electron Phonon Interaction ◽  
Layer Graphene ◽  
A Value ◽  
Few Layer Graphene

Abstract The defects into the hexagonal network of a sp2-hybridized carbon atom have been demonstrated to have a significant influence on intrinsic properties of graphene systems. In this paper, we presented a study of temperature-dependent Raman spectra of G peak and D’ band at low temperatures from 78 to 318 K in defective monolayer to few-layer graphene induced by ion C+ bombardment under the determination of vacancy uniformity. Defects lead to the increase of the negative temperature coefficient of G peak, with a value almost identical to that of D’ band. However, the variation of frequency and linewidth of G peak with layer number is contrary to D’ band. It derives from the related electron-phonon interaction in G and D’ phonon in the disorder-induced Raman scattering process. Our results are helpful to understand the mechanism of temperature-dependent phonons in graphene-based materials and provide valuable information on thermal properties of defects for the application of graphene-based devices.

scholarly journals Selectivity of Tungsten Oxide Synthesized by Sol-Gel Method Towards Some Volatile Organic Compounds and Gaseous Materials in a Broad Range of Temperatures

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 523 ◽  
Author(s):  
Simonas Ramanavičius ◽  
Milda Petrulevičienė ◽  
Jurga Juodkazytė ◽  
Asta Grigucevičienė ◽  
Arūnas Ramanavičius
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Sol Gel ◽  
Temperature Dependent ◽  
Sensing Systems ◽  
Sensing Material ◽  
Operational Temperature ◽  
Volatile Organic ◽  
Different Gases

In this research, the investigation of sensing properties of non-stoichiometric WO3 (WO3−x) film towards some volatile organic compounds (VOC) (namely: Methanol, ethanol, isopropanol, acetone) and ammonia gas are reported. Sensors were tested at several temperatures within the interval ranging from a relatively low temperature of 60 up to 270 °C. Significant variation of selectivity, which depended on the operational temperature of sensor, was observed. Here, the reported WO3/WO3–x-based sensing material opens an avenue for the design of sensors with temperature-dependent sensitivity, which can be applied in the design of new gas- and/or VOC-sensing systems that are dedicated for the determination of particular gas- and/or VOC-based analyte concentration in the mixture of different gases and/or VOCs, using multivariate analysis of variance (MANOVA).

scholarly journals A Direct Method to Extract Transient Sub-Gap Density of State (DOS) Based on Dual Gate Pulse Spectroscopy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Mingzhi Dai ◽  
Karim Khan ◽  
Shengnan Zhang ◽  
Kemin Jiang ◽  
Xingye Zhang ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Integrated Circuits ◽  
Direct Method ◽  
Temperature Dependent ◽  
Extrinsic Factors ◽  
Gate Pulse ◽  
Dual Gate ◽  
Pulse Spectroscopy ◽  
A Direct Method ◽  
Peak Value

Abstract Sub-gap density of states (DOS) is a key parameter to impact the electrical characteristics of semiconductor materials-based transistors in integrated circuits. Previously, spectroscopy methodologies for DOS extractions include the static methods, temperature dependent spectroscopy and photonic spectroscopy. However, they might involve lots of assumptions, calculations, temperature or optical impacts into the intrinsic distribution of DOS along the bandgap of the materials. A direct and simpler method is developed to extract the DOS distribution from amorphous oxide-based thin-film transistors (TFTs) based on Dual gate pulse spectroscopy (GPS), introducing less extrinsic factors such as temperature and laborious numerical mathematical analysis than conventional methods. From this direct measurement, the sub-gap DOS distribution shows a peak value on the band-gap edge and in the order of 1017–1021/(cm3·eV), which is consistent with the previous results. The results could be described with the model involving both Gaussian and exponential components. This tool is useful as a diagnostics for the electrical properties of oxide materials and this study will benefit their modeling and improvement of the electrical properties and thus broaden their applications.

scholarly journals Temperature Dependence of Electrical Properties and Crystal Structure of 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Qian Li ◽  
Yun Liu ◽  
Andrew Studer ◽  
Zhenrong Li ◽  
Ray Withers ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electrical Properties ◽  
Dielectric Permittivity ◽  
Neutron Diffraction ◽  
Electrical Measurement ◽  
Temperature Dependent ◽  
Electromechanical Properties ◽  
Polar Order

We characterized the temperature dependent (~25–200°C) electromechanical properties and crystal structure of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3single crystals usingin situelectrical measurement and neutron diffraction techniques. The results show that the poled crystal experiences an addition phase transition around 120°C whereas such a transition is absent in the unpoled crystal. It is also found that the polar order persists above the maximum dielectric permittivity temperature at which the crystal shows a well-defined antiferroelectric behavior. The changes in the electrical properties and underlying crystal structure are discussed in the paper.

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