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Title: Electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S rare-earth semiconductors

Abstract

The electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S compounds are studied. The conductivity, concentration of free electrons, their mobility, and the conductivity activation energy are measured as functions of the quantity x. The structural parameters of the compounds are determined. A heterostructure is fabricated with x in the range from 0 to 0.3, and the electrical voltage generated by the structure, when heated to a temperature of T = 450 K, due to the thermovoltaic effect is measured. This voltage is found to be 55 mV. A method for measuring the thermally induced voltage is described. The method provides a means for separating the thermovoltaic effect from the Seebeck effect.

Authors:
; ; ; ;  [1]
  1. Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)
Publication Date:
OSTI Identifier:
22649713
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 50; Journal Issue: 9; Other Information: Copyright (c) 2016 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; CARRIER MOBILITY; CONCENTRATION RATIO; ELECTRIC CONDUCTIVITY; ELECTRIC POTENTIAL; ELECTRONS; EUROPIUM COMPOUNDS; POLYCRYSTALS; SAMARIUM SULFIDES; SEEBECK EFFECT; SEMICONDUCTOR MATERIALS; TEMPERATURE DEPENDENCE

Citation Formats

Kaminskii, V. V., E-mail: vladimir.kaminski@mail.ioffe.ru, Kazanin, M. M., Romanova, M. V., Kamenskaya, G. A., and Sharenkova, N. V.. Electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S rare-earth semiconductors. United States: N. p., 2016. Web. doi:10.1134/S1063782616090116.
Kaminskii, V. V., E-mail: vladimir.kaminski@mail.ioffe.ru, Kazanin, M. M., Romanova, M. V., Kamenskaya, G. A., & Sharenkova, N. V.. Electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S rare-earth semiconductors. United States. doi:10.1134/S1063782616090116.
Kaminskii, V. V., E-mail: vladimir.kaminski@mail.ioffe.ru, Kazanin, M. M., Romanova, M. V., Kamenskaya, G. A., and Sharenkova, N. V.. Thu . "Electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S rare-earth semiconductors". United States. doi:10.1134/S1063782616090116.
@article{osti_22649713,
title = {Electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S rare-earth semiconductors},
author = {Kaminskii, V. V., E-mail: vladimir.kaminski@mail.ioffe.ru and Kazanin, M. M. and Romanova, M. V. and Kamenskaya, G. A. and Sharenkova, N. V.},
abstractNote = {The electrical parameters of polycrystalline Sm{sub 1–x}Eu{sub x}S compounds are studied. The conductivity, concentration of free electrons, their mobility, and the conductivity activation energy are measured as functions of the quantity x. The structural parameters of the compounds are determined. A heterostructure is fabricated with x in the range from 0 to 0.3, and the electrical voltage generated by the structure, when heated to a temperature of T = 450 K, due to the thermovoltaic effect is measured. This voltage is found to be 55 mV. A method for measuring the thermally induced voltage is described. The method provides a means for separating the thermovoltaic effect from the Seebeck effect.},
doi = {10.1134/S1063782616090116},
journal = {Semiconductors},
number = 9,
volume = 50,
place = {United States},
year = {Thu Sep 15 00:00:00 EDT 2016},
month = {Thu Sep 15 00:00:00 EDT 2016}
}
  • The rare-earth based nickelates RNiO{sub 3} (R = Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R{sup 3+} site within the electronic ground-state J multiplet (for R = Pr, Nd, and Pr{sub 1-x}La{sub x}) as well as within the two lowest-lying J multiplets (for R = Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with themore » R sublattice in agreement with results from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF parameters in an effective point charge model failed, probably due to the strong covalency in these compounds. Across the structural transition occurring in Pr{sub 1-x}La{sub x}NiO{sub 3} at x = 0.7, a change in the symmetry of the CEF ground state is observed which has a profound influence on the thermodynamic properties.« less
  • The rare-earth based nickelates RNiO{sub 3} (R=Pr, Nd, Sm, Eu, and Pr{sub 1-x}La{sub x}, 0{<=}x{<=}0.7) were studied by inelastic neutron scattering. Energy splittings due to the crystalline-electric-field (CEF) interaction at the R{sup 3+} site within the electronic ground-state J multiplet (for R=Pr, Nd, and Pr{sub 1-x}La{sub x}) as well as within the two lowest-lying J multiplets (for R=Sm and Eu) were directly observed, and the corresponding CEF energy-level schemes were reconstructed. The latter were rationalized in terms of CEF parameters, which vary smoothly over the rare-earth series and give magnetic properties associated with the R sublattice in agreement with resultsmore » from neutron powder diffraction experiments. Across the metal-insulator transition, a continuous change in the electronic part of the CEF parameters is observed. However, an attempt to quantify a charge transfer from the observed variation of the CEF parameters in an effective point charge model failed, probably due to the strong covalency in these compounds. Across the structural transition occurring in Pr{sub 1-x}La{sub x}NiO{sub 3} at x=0.7, a change in the symmetry of the CEF ground state is observed, which has a profound influence on the thermodynamic properties. (c) 1999 The American Physical Society.« less
  • Mixed compounds (Gd[sub 1[minus][ital x]R[ital x]])[sub 2]CuO[sub 4], [ital R]=Pr, Nd, Sm, and Eu, with [ital T][prime] structure, were studied by x-ray diffraction and by [sup 155]Gd Moessbauer spectroscopy. Structural parameters (unit cell volume, [ital c]/3[ital a]) differ considerably for compounds with different rare earths. In contrast, the variation of the isomer shift [delta][sub [ital I][ital S]] and of the electric-field gradient [ital V][sub [ital z][ital z]] at [sup 155]Gd nuclei with Gd concentration is practically identical in the systems with Pr, Nd, and Sm. These results demonstrate that [delta][sub [ital I][ital S]] and [ital V][sub [ital z][ital z]] inmore » the compounds [ital R][sub 2]CuO[sub 4] are primarily determined by contributions of the local electronic-charge distribution at the rare-earth site, which depends weakly upon the positions of the ions as determined by the structural parameters. Furthermore, our results indicate the possibility of an influence of the degree of covalency upon the transition temperature [ital T][sub [ital c]] achieved in Ce-doped compounds.« less
  • Binary lanthanum sulfides with compositions between La/sub 2/S/sub 3/ and La/sub 3/S/sub 4/ form a continuous series of solid solutions in the high temperature gamma form and have been reported to have high figures of merit. In this study, in order to achieve increased stability of the gamma form, compounds with the formula La/sub 3-x/M/sub x/S/sub 4/ (M = Sm, Eu, Tb and x = 0.1 to 0.9) were prepared. The Seebeck coefficients and electrical resistivities of these ternary sulfides are reported as well as some preliminary results on their long term thermal stability. The compounds La/sub 3-x/M/sub x/S/sub 4/more » (M = Sm, Eu, Yb and x = 0.1 to 0.9) prepared in this study all possessed the high temperature ..gamma..-Th/sub 3/P/sub 4/ structure and the compounds with small values of x possessed attractive thermoelectric properties. The figure of merit at 1000/sup 0/C of these compounds is in the neighborhood of 0.7 to 0.8 x 10/sup -3/ /sup 0/C/sup -1/ when the thermal conductivity is taken to be 15 mW/sup 0/C/sup -1/cm/sup -1/ and is comparable to that of binary LaS/sub x/ and SiGe alloys. Long term vaporiation data indicate that these materials are stable in vacuum for an extended period of time. 12 refs., 4 figs., 1 tab.« less
  • A systematic study of Zn doping on the resistivity {rho}, dc susceptibility {chi}, and superconducting {ital T}{sub {ital c}} of {ital R}Ba{sub 2}Cu{sub 3{minus}{ital x}}Zn{sub {ital x}}O{sub 7{minus}{ital y}} systems ({ital R}=Yb, Er Y, Dy, Gd, Eu, Sm, and Nd, and 0{le}{ital x}{le}0.3) is reported. X-ray powder diffraction (XRD) shows that all samples consist essentially of a single phase and retain the orthorhombic structure in the range of 0{le}{ital x}{le}0.3 (except for {ital R}=Yb in the range of 0{le}{ital x}{le}0.15). By analyzing our Raman spectra and XRD data, Zn atoms are found more likely to substitute on Cu(2) sites. Dopingmore » with Zn on the Cu site in these systems causes a rapid nearly linear decrease of {ital T}{sub {ital c}} as Zn content increases. The reduction of {ital T}{sub {ital c}} for {ital R}Ba{sub 2}Cu{sub 3{minus}{ital x}}Zn{sub {ital x}}O{sub 7{minus}{ital y}} is found to depend strongly on the ionic radius of the rare-earth element {ital R}. This effect resembles the ion size effect on {ital T}{sub {ital c}} in {ital R}{sub 1{minus}{ital x}}Pr{sub {ital x}}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{ital y}}, where Pr substitutes on the {ital R} site, and in {ital R}Ba{sub 2}Cu{sub 3{minus}{ital x}}Ga{sub {ital x}}O{sub 7{minus}{ital y}}, where Ga substitutes on the Cu(1) sites in Cu-O chains, although in the {ital R}Ba{sub 2}Cu{sub 3{minus}{ital x}}Zn{sub {ital x}}O{sub 7{minus}{ital y}} systems Zn is found to be more likely to substitute on the Cu(2) sites in Cu-O{sub 2} planes. The suppression of superconductivity by zinc and the rare-earth ion size effect on {ital T}{sub {ital c}} in these systems is interpreted in terms of a Mott spin bipolaron model. {copyright} {ital 1996 The American Physical Society.}« less