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Study contribution of low temperature properties of KTaO{sub 3} based compounds by thermal and dielectric measurements; Contribution a l`etude des proprietes basse temperature des composes a base de KTaO{sub 3} par mesures thermiques et dielectriques

Abstract

This work is centered on experimental study of the thermal transport of KTaO{sub 3} compounds, characterized by one optical mode presence which softens when temperature decreases. Thermal conductivities of non-doped and doped with polarizing ions (Nb, Na, Li) compounds were specially studied. Acoustical phonons are strongly diffused near 7 K. This resonance was assigned to an interaction between thermal phonons with the soft optical mode, made possible in region where a structural disorder exists. This disorder is locally created by impurities centers, the nature of which we determine by dielectric measurements and by electron paramagnetic resonance. From a more microscopic point of view, we propose to associate the Libron concept to this defect, and we try to make a connection between the observed disorder effects in KTaO{sub 3} and disordered systems physics (Glasses).
Authors:
Publication Date:
Jul 01, 1991
Product Type:
Thesis/Dissertation
Report Number:
FRCEA-TH-356
Reference Number:
SCA: 665100; PA: FRD-92:000965; SN: 92000757218
Resource Relation:
Other Information: TH: These (D. es Sc.); PBD: Jul 1991
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; FERROMAGNETIC MATERIALS; THERMAL CONDUCTIVITY; POTASSIUM OXIDES; TANTALUM OXIDES; CUBIC LATTICES; PHONONS; SPECIFIC HEAT; THERMAL EXPANSION; TEMPERATURE DEPENDENCE; DOPED MATERIALS; NIOBIUM; SODIUM; LITHIUM; DIELECTRIC PROPERTIES; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0013-0065 K; TEMPERATURE RANGE 0065-0273 K; 665100; NUCLEAR TECHNIQUES IN CONDENSED MATTER PHYSICS
OSTI ID:
10150640
Research Organizations:
CEA Centre d`Etudes Nucleaires de Grenoble, 38 (France). Dept. de Recherche Fondamentale; Grenoble-1 Univ., 38 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
Other: ON: DE92526923; TRN: FR9200965
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
FRN
Size:
160 p.
Announcement Date:
Jul 05, 2005

Citation Formats

Gravil, J L. Study contribution of low temperature properties of KTaO{sub 3} based compounds by thermal and dielectric measurements; Contribution a l`etude des proprietes basse temperature des composes a base de KTaO{sub 3} par mesures thermiques et dielectriques. France: N. p., 1991. Web.
Gravil, J L. Study contribution of low temperature properties of KTaO{sub 3} based compounds by thermal and dielectric measurements; Contribution a l`etude des proprietes basse temperature des composes a base de KTaO{sub 3} par mesures thermiques et dielectriques. France.
Gravil, J L. 1991. "Study contribution of low temperature properties of KTaO{sub 3} based compounds by thermal and dielectric measurements; Contribution a l`etude des proprietes basse temperature des composes a base de KTaO{sub 3} par mesures thermiques et dielectriques." France.
@misc{etde_10150640,
title = {Study contribution of low temperature properties of KTaO{sub 3} based compounds by thermal and dielectric measurements; Contribution a l`etude des proprietes basse temperature des composes a base de KTaO{sub 3} par mesures thermiques et dielectriques}
author = {Gravil, J L}
abstractNote = {This work is centered on experimental study of the thermal transport of KTaO{sub 3} compounds, characterized by one optical mode presence which softens when temperature decreases. Thermal conductivities of non-doped and doped with polarizing ions (Nb, Na, Li) compounds were specially studied. Acoustical phonons are strongly diffused near 7 K. This resonance was assigned to an interaction between thermal phonons with the soft optical mode, made possible in region where a structural disorder exists. This disorder is locally created by impurities centers, the nature of which we determine by dielectric measurements and by electron paramagnetic resonance. From a more microscopic point of view, we propose to associate the Libron concept to this defect, and we try to make a connection between the observed disorder effects in KTaO{sub 3} and disordered systems physics (Glasses).}
place = {France}
year = {1991}
month = {Jul}
}