ABSORPTION SPECTROSCOPY OF ELECTRONIC STATES NEAR FERMI LEVEL: TEMPERATURE CHANGES OF SUPERCONDUCTING YBa2Cu3O7−δ FILMS AT Tc

1992 ◽  
Vol 06 (09) ◽  
pp. 1475-1489 ◽  
Author(s):  
I. YA. FUGOL ◽  
V.N. SAMOVAROV ◽  
YU. I. RYBALKO ◽  
V.M. ZHURAVLEV
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Energy Region ◽  
Local Level ◽  
Electronic States ◽  
Superconducting Transition ◽  
Temperature Dependent ◽  
Temperature Changes ◽  
Optical Gap ◽  
Dependent Behaviour

The temperature behavior of the absorption spectra of superconducting YBa 2Cu3O7−δ textured films is measured in a 1.5÷3.0 eV energy region with varying temperatures from 25 to 300 K. The spectra are found to be sensitive to a superconducting transition: the temperature-dependent behaviour of absorption at T>Tc undergoes critical changes under the superconducting transition and for T<Tc the spectrum ceases to depend on temperature. The spectra display an exciton maximum in the optical gap Eg=1.95 eV. The spectrum freezing at T<Tc can be explained assuming that the Fermi level is in temperature resonance with a narrow local level which is responsible for a delta-like singularity in the density of states.

Temperature Dependent Defect Density Calculated from Activated Conductivity of a-Si:H

1991 ◽  
Vol 219 ◽  
Author(s):  
T. Drusedau ◽  
V. Kirbs ◽  
H. Fiedler
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Defect Density ◽  
State Density ◽  
Level Shift ◽  
Defect State ◽  
Temperature Dependent ◽  
Slow Cooling ◽  
Thermally Activated ◽  
Gap States

ABSTRACTThermally activated conductivity of a—Si:H at a slow cooling rate of 0.3 K/min is connected with temperature dependent changes of the mobility gap states. By means of the Fermi—level shift calculated from these data and a density of states model it is possible to determine this dependence. The results mainly reveal a decrease of the defect state density by about a tenth between 375 K and 400 K.

Modeling And Photoabsorption Study of YPd2-xRhxB2C Superconductors

2002 ◽  
Vol 731 ◽  
Author(s):  
L.-S. Hsu ◽  
Y. K. Wang ◽  
G. Y. Guo ◽  
Y.-J. Huang ◽  
M.-D. Lan
Keyword(s):  
Fermi Level ◽  
Intermetallic Compounds ◽  
Density Of States ◽  
Electronic Structures ◽  
Theoretical Calculations ◽  
Photoemission Spectrum ◽  
Partial Density ◽  
Superconducting Transition ◽  
X Ray ◽  
X Ray Absorption

AbstractThe electronic structures of six polycrystalline borocarbide superconductors YPd5-xRhxB3C0.4 (x=0, 0.05, 0.1, 0.15, 0.2, and 0.25) were studied by photoemission and photoabsorption spectroscopies and theoretical calculations. The valence-band (VB) photoemission spectrum is compared with the theoretical total and partial density-of-states (DOS) curves. The Pd L3-edge x-ray absorption near edge spectra (XANES) are compared with the calculated XANES spectra for these intermetallic compounds. The decrease of the superconducting transition temperatures (Tc) with addition of Rh dopant in these compounds is due to a decrease of the total DOS at the Fermi level (EF).

scholarly journals Automotive MR Shock Absorber Behaviour Considering Temperature Changes: Experimental Testing and Analysis

2020 ◽  
Vol 14 (1) ◽  
pp. 22-28
Author(s):  
Łukasz Jastrzębski ◽  
Bogdan Sapiński ◽  
Arkadiusz Kozieł
Keyword(s):  
Temperature Dependence ◽  
Shock Absorber ◽  
Mechanical Performance ◽  
Experimental Testing ◽  
Temperature Dependent ◽  
Temperature Changes ◽  
Coil Temperature ◽  
Operating Current ◽  
Coil Resistance ◽  
Dependent Behaviour

AbstractThis study investigates the automotive magnetorheological (MR) shock absorber behaviour in conditions of changing temperature. Its temperature-dependent behaviour was quantified between ambient and maximal operating temperatures of the device. Aspects addressed include the temperature dependence of the control coil resistance in the absorber, the influence of operating current level on control coil temperature and the temperature dependence of the absorber force response and energy dissipation in the system. The results of experiments enabled us to evaluate the mechanical performance of the absorber at varied temperatures.

scholarly journals REVERSIBLE CHANGES OF EDGE Π-ELECTRONIC STATES OF MULTILAYER GRAPHENE NANOCLUSTERS UNDER INFLUENCE OF ADSORBED CHLORINE MOLECULES

2018 ◽  
Vol 59 (9) ◽  
pp. 4 ◽  
Author(s):  
Albert M. Ziatdinov ◽  
Nikita S. Saenko ◽  
Peter G Skrylnik
Keyword(s):  
Activated Carbon ◽  
Fermi Level ◽  
Density Of States ◽  
Carbon Fibers ◽  
Electronic States ◽  
Spin Splitting ◽  
Multilayer Graphene ◽  
Activated Carbon Fibers ◽  
Partial Transfer ◽  
Structural Blocks

The reversible decrease in the density of states of current carriers D(EF) at the Fermi level EF for nanographites - structural blocks of activated carbon fibers, at their interaction with adsorbed chlorine molecules, has been found. It has been shown that this effect can be explained by the spin-splitting of edge π-electronic states in nanographites induced by the enhancement of electron-electron interactions due to increase in the D(EF) at partial transfer of the electron density from adsorbent to adsorbate. The revealed irreversible decrease in the concentration of localized spins at nanographite chlorination indicates that the spins of electrons of unsaturated (dangling) σ-orbitals of edge carbon atoms and those of chlorine 3p-orbitals are coupled at this interaction, i.e. the edge covalent compound of nanographite with chlorine forms.

Electronic States near the Fermi Level in the Antiferromagnetic and Ferromagnetic Spinels of Zn 1− x Cu x Cr 2 Se 4 ; 0.0 ≤ x ≤ 1.0

2002 ◽  
Vol 75 (4-5) ◽  
pp. 359-371
Author(s):  
M. Hidaka ◽  
N. Tokiwa ◽  
M. Yoshimura ◽  
H. Fujii ◽  
Jae-Young Choi ◽  
...  
Keyword(s):  
Fermi Level ◽  
Electronic States

scholarly journals Investigation of single-domain Au silicide nanowires on Si(110) formed for Au coverages in the monolayer regime

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephan Appelfeller
Keyword(s):  
Fermi Level ◽  
Surface Structure ◽  
Density Of States ◽  
The Self ◽  
Single Domain ◽  
Photoemission Spectroscopy ◽  
Annealing Temperatures ◽  
Self Organized ◽  
Scanning Tunnelling ◽  
Tunnelling Microscopy

AbstractThe self-organized formation of single domain Au silicide nanowires is observed on Si(110). These nanowires are analysed using scanning tunnelling microscopy (STM) and spectroscopy (STS) as well as photoemission spectroscopy (PES). Core-level PES is utilised to confirm the formation of Au silicide and establish its presence as the top most surface structure, i.e., the nanowires. The growth of the Au silicide nanowires and their dimensions are studied by STM. They form for Au coverages of about 1 monolayer and are characterized by widths of about 2 to 3 nm and heights below 1 nm while reaching lengths exceeding 500 nm when choosing appropriate annealing temperatures. Valence band PES and STS indicate a small but finite density of states at the Fermi level typical for compound metals.

Photosensitive tunneling in superconductivity

1970 ◽  
Vol 48 (5) ◽  
pp. 630-631 ◽  
Author(s):  
V. Radhakrishnan
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Tunneling Current ◽  
Theoretical Treatment ◽  
Photoconductive Property

Theoretical treatment of the model proposed by Giaever for his experiment on the photosensitive tunneling in superconductors is examined. New relations are derived which connect the photoconductive property of the barrier and the tunneling current. These relations are helpful to check the model and to determine the density of states for the trapped holes at the hole Fermi level.

Temperature-Dependent Photoluminescence Spectra of PbSe Quantum Dots for Temperature Markers

2012 ◽  
Vol 482-484 ◽  
pp. 2547-2550
Author(s):  
Peng Fei Gu ◽  
Ya Nan Wang ◽  
Jia Jia Cao ◽  
Yu Yan ◽  
Tie Qiang Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Temperature Sensitivity ◽  
Peak Position ◽  
Strong Temperature Dependence ◽  
Photoluminescence Spectra ◽  
Temperature Dependent ◽  
Temperature Variations ◽  
Temperature Changes ◽  
Optical Readout ◽  
Temperature Dependent Photoluminescence

We here report the temperature effect on photoluminescence(PL) spectra of PbSe quantum dots (QDs), which exhibit a strong temperature dependence on their spectra position and intensity. They potentially act as the temperature marker, sensing temperature variations and reporting temperature changes remotely through optical readout. In addition, the temperature sensitivity characterized by peak position of PbSe QDs was found to be 0.39nm/°C in a range of 10-100 °C.

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