scholarly journals Термический коэффициент движения резонансного уровня железа в сплавах Pb-=SUB=-1-x-y-=/SUB=-Sn-=SUB=-x-=/SUB=-Fe-=SUB=-y-=/SUB=-Te

2019 ◽  
Vol 53 (11) ◽  
pp. 1459
Author(s):  
Е.П. Скипетров ◽  
Б.Б. Ковалев ◽  
Л.А. Скипетрова ◽  
А.В. Кнотько ◽  
В.Е. Слынько
Keyword(s):  
Electronic Structure ◽  
Valence Band ◽  
Hall Coefficient ◽  
Iron Level ◽  
Anomalous Temperature ◽  
Resonant Level ◽  
Structure Rearrangement ◽  
Temperature Dependences ◽  
Normal Spectrum ◽  
Increasing Temperature

The phase composition, the elemental composition and temperature dependences of the resistivity and of the Hall coefficient (temperature interval 4.2≤T≤300K, magnetic fields B≤0.07 T) in Pb1−x−ySnxFeyTe alloys are studied at variation of the tin and iron concentrations along the single-crystal ingots synthesized by the Bridgman−Stockbarger technique. The distributions of tin and iron along the ingots are obtained and anomalous temperature dependences of the Hall coefficient, associated with the pinning of the Fermi level by the resonant level of iron, located in the valence band, are found. The analysis of the experimental results is carried out in the framework of the model of the electronic structure rearrangement, involving the movement of the iron level relative to the top of the valence band with increasing tin concentration and temperature. The temperature coefficient of the movement of the level of iron with respect to the middle of the gap is determined and the possible diagrams for the rearrangement of the electronic structure with increasing temperature in the alloys with normal spectrum (0.06≤x≤0.35) are proposed.

scholarly journals Влияние примеси никеля на гальваномагнитные свойства и электронную структуру PbTe

2020 ◽  
Vol 54 (10) ◽  
pp. 987
Author(s):  
Е.П. Скипетров ◽  
Б.Б. Ковалев ◽  
И.В. Шевченко ◽  
А.В. Кнотько ◽  
В.Е. Слынько
Keyword(s):  
Electronic Structure ◽  
Hall Coefficient ◽  
Impurity Concentration ◽  
Inversion Layer ◽  
Impurity Band ◽  
Anomalous Temperature ◽  
Conduction Mechanisms ◽  
Galvanomagnetic Properties ◽  
Temperature Dependences ◽  
Increasing Temperature

The phase and elemental composition and galvanomagnetic properties (4.2 < T < 300 K, B < 7 T) of Pb1-yNiyTe alloys are studied at a variation of the nickel impurity concentration along the single-crystal ingot synthesized by the Bridgman-Stockbarger technique. It is shown that the solubility of nickel does not exceed 0.35 mol %. Anomalous temperature dependences of the Hall coefficient and temperature and field dependences of magnetoresistance are found. To explain the results, it is assumed that an n-type inversion layer appears on the surface of the samples and that there are several competing conduction mechanisms in the samples. A model of the Pb1-yNiyTe electronic structure is proposed that assumes pinning of the Fermi level within the Ni impurity band, located at the edge of the valence band and moving deeper into it with increasing temperature.

scholarly journals Кинетика изменения концентраций магнитных ионов примеси в сплавах Pb-=SUB=-1-x-y-=/SUB=-Sn-=SUB=-x-=/SUB=-V-=SUB=-y-=/SUB=-Te при легировании

2018 ◽  
Vol 52 (7) ◽  
pp. 686
Author(s):  
Е.П. Скипетров ◽  
Н.С. Константинов ◽  
Л.А. Скипетрова ◽  
А.В. Кнотько ◽  
В.Е. Слынько
Keyword(s):  
Electronic Structure ◽  
Crystal Lattice ◽  
X Ray ◽  
Structure Rearrangement ◽  
Galvanomagnetic Properties ◽  
Temperature Dependences ◽  
Stockbarger Method ◽  
Diamagnetic Contribution ◽  
Magnetic States ◽  
Vanadium Ions

AbstractThe field and temperature dependences of the magnetization (magnetic fields B ≤ 7.5 T, temperatures T = 2.0–75 K) of samples from a Pb_1– x – y Sn_ x V_ y Te ( x = 0.08, y = 0.01) single-crystal ingot synthesized by the Bridgman–Stockbarger method. It is established that the sample magnetization contains two main contributions, notably, the paramagnetism of vanadium ions and diamagnetism of the crystal lattice. The field and temperature dependences of the magnetization are approximated by the sum of modified Brillouin functions corresponding to the paramagnetic contributions of vanadium in two different charge states and the diamagnetic contribution linear in terms of field. The concentrations of vanadium ions in two different magnetic states and the character of their variation along the ingot are determined within the scope of the alloy’s electronic-structure rearrangement because of doping. The results are compared with the data of X-ray fluorescence microanalysis and the results of studying the galvanomagnetic properties of the samples.

scholarly journals Гальваномагнитные свойства моносилицида кобальта и сплавов на его основе

2019 ◽  
Vol 53 (6) ◽  
pp. 746
Author(s):  
А.Ю. Овчинников ◽  
П.П. Константинов ◽  
Д.А. Пшенай-Северин ◽  
А.Т. Бурков
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Hall Coefficient ◽  
Fermi Energy ◽  
Theoretical Interpretation ◽  
Compound A ◽  
Topological Features ◽  
Temperature Dependences ◽  
Small Overlap ◽  
Ab Initio Electronic Structure

In this work, we study the Hall coefficient and the conductivity of cobalt monosilide CoSi, as well as Co1−xFexSi and Co1−xNixCo alloys with contents up to 8 at% of iron and up to 5 at% of nickel. The temperature dependences of the Hall coefficient and of the conductivity were measured in the temperature range of 77−800K. The theoretical interpretation of the experimental dependencies is based on two different models of the electronic structure of the compound: a simple 2-band semimetallic structure with small overlap of isotropic parabolic bands; and ab initio electronic structure, containing near Fermi energy topological features with multiply degenerate intersections of bands.

Galvanomagnetic and Magnetic Properties of Pb1-yScyTe

2015 ◽  
Vol 233-234 ◽  
pp. 97-100 ◽  
Author(s):  
E.P. Skipetrov ◽  
M.M. Markina ◽  
K.V. Zakharov ◽  
L.A. Skipetrova ◽  
A.A. Solovev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Impurity Content ◽  
Free Electron Concentration ◽  
Resonant Level ◽  
Structure Rearrangement ◽  
Galvanomagnetic Properties ◽  
Weak Magnetic Fields ◽  
Heavily Doped

The galvanomagnetic properties in weak magnetic fields (4.2≤T≤300 K, B≤0.07 T) as well as magnetic properties (2≤T≤300 K, B≤9 T) of the single-crystal Pb1-yScyTe (y≤0.02) alloys have been investigated. We find that an increase of Sc impurity content leads to a monotonous growth of the free electron concentration (from 1016 cm-3 to 1020 cm-3). In heavily doped alloys (y>0.01), it tends to saturation, indicating the pinning of the Fermi energy by the scandium resonant level located inside the conduction band. The energy of the level is estimated (ESc≈Ec+280 meV) and the model of electronic structure rearrangement of Pb1-yScyTe alloys with doping is proposed. In the frame of this model, using experimental temperature and magnetic field dependences of magnetization, the concentrations of magnetically active scandium ions are determined and connection of the electronic structure with the magnetic properties of the alloys are discussed.

scholarly journals Magnetic properties of Pb1-x-ySnxVyTe alloys

2018 ◽  
Vol 185 ◽  
pp. 06010
Author(s):  
Evgeny Skipetrov ◽  
Nikita Konstantinov ◽  
Liudmila Skipetrova ◽  
Alexander Knotko ◽  
Vasily Slynko
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Theoretical Model ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Impurity Concentration ◽  
Bridgman Method ◽  
Structure Rearrangement ◽  
Temperature Dependences ◽  
Vanadium Ions

We study the field and temperature dependences of the magnetization (B≤7.5 T, T=2.0-75 K) of samples from a single crystal Pb1-x-ySnxVyTe (x=0.08, y=0.01) ingot synthesized by the Bridgman method. It is established that the magnetization of the samples contains two main contributions: the Brillouin-type paramagnetism of vanadium ions and the diamagnetism of the crystal lattice. Experimental field and temperature dependences of the magnetization are discussed in the framework of a theoretical model of electronic structure rearrangement in Pb1-x-ySnxVyTe with doping and approximated as the sums of two terms based on the modified Brillouin functions for vanadium ions in the V3+ and V2+ states. The concentrations of magnetically active vanadium ions in two different charge states with increasing impurity concentration along the ingot are determined.

A photoemission investigation of the valence band electronic structure of and

1997 ◽  
Vol 9 (14) ◽  
pp. 2955-2961 ◽  
Author(s):  
D Brown ◽  
M D Crapper ◽  
K H Bedwell ◽  
M Petty ◽  
J G Smith ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Valence Band

scholarly journals Determination of Conduction and Valence Band Electronic Structure of LaTiO x N y Thin Film

ChemSusChem ◽  
2017 ◽  
Vol 10 (9) ◽  
pp. 2099-2106 ◽  
Author(s):  
Markus Pichler ◽  
Jakub Szlachetko ◽  
Ivano E. Castelli ◽  
Nicola Marzari ◽  
Max Döbeli ◽  
...  
Keyword(s):  
Thin Film ◽  
Electronic Structure ◽  
Valence Band

scholarly journals Determination of the valence band edge of Fe oxide nanoparticles dispersed in aqueous solution through resonant photoelectron spectroscopy from a liquid microjet

2021 ◽  
Author(s):  
Giorgia Olivieri ◽  
Gregor Kladnik ◽  
Dean Cvetko ◽  
Matthew A. Brown
Keyword(s):  
Aqueous Solution ◽  
Electronic Structure ◽  
Valence Band ◽  
Photoelectron Spectroscopy ◽  
Band Edge ◽  
Photoemission Spectroscopy ◽  
Oxide Nanoparticles ◽  
Valence Band Edge ◽  
Resonant Photoemission

The electronic structure of hydrated nanoparticles can be unveiled by coupling a liquid microjet with a resonant photoemission spectroscopy.

scholarly journals Thermodynamic Parameters of PbTe Crystals: DFT-Calculations

2015 ◽  
Vol 16 (1) ◽  
pp. 28-33
Author(s):  
D. M. Freik ◽  
B. P. Volochanska ◽  
T. O. Parashchuk
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Electronic Structure ◽  
Thermodynamic Parameters ◽  
Quantum Chemical ◽  
Density Functional ◽  
Cubic Phase ◽  
Functional Theory ◽  
Temperature Dependences ◽  
Analytical Expressions

Based on the analysis of the crystal NaCl type and electronic structure of cubic phase CdS crystals the cluster models have been built for calculation of the geometric and thermodynamic parameters. According to density functional theory (DFT) and using the hybrid valence base set B3LYP the temperature dependence of the energy ΔE and the enthalpy ΔH of formation, Gibbs free energy ΔG, entropy ΔS, specific heat at constant volume CV and pressure CP of the crystals have been found. The analytical expressions of the temperature dependences of presented thermodynamic parameters which was approximated from the quantum- chemical calculations data and with using mathematical package Maple 14 have been received.

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