Struktura krystaliczna i właściwości elektryczne BIMGVOX-u

Marcin Małys

Abstract

The structural and electrical properties of new oxide ionic conductor BIMGVOX (Bi4Mg2xV22xOll-3x) have been investigated. The characterisation of structure, carried out by means of Xray and neutron powder diffraction, allowed to determine symmetry and lattice parameters as a function of the composition of studied material. Several compositionally and thermally dependent structural polymorphs have been detected (orthorhombic a i p, tetragonal y i y'). It was shown that the stabilisation of tetragonal y phase at high (above 500°C) to lower temperatures takes place for composition range of 0.10 < x < 0.25. The electrical conductivity measurements have been carried out by a.c. impedance spectroscopy. The highest conductivity at low temperature region (1.54.10-3 Scm-l at 300°C) was achieved for x = 0.13 composition. To determine the conductivity mechanism of oxide ions in BIMGVOX the defect structure of oxide sublattice was studied. The obtained data allowed for the determination of the positions of different atoms and their occupancies in the crystal structure it was shown that conductivity of BIMGVOX is mainly affected by two factors: the oxide vacancies concentration and the extent of defect trapping effect.
Diploma typeDoctor of Philosophy
Author Marcin Małys (FP / SSID)
Marcin Małys,,
- Solid State Ionics Division
Title in PolishStruktura krystaliczna i właściwości elektryczne BIMGVOX-u
Languagepl polski
Certifying UnitFaculty of Physics (FP)
Disciplinephysics / (physical sciences domain) / (physical sciences)
Defense Date01-01-2001
Supervisor Franciszek Krok (FP / SSID)
Franciszek Krok,,
- Solid State Ionics Division

Pages117
Keywords in Polishbadania strukturalne kryształów, dyfraktometria neutronowa, dyfraktometria rentgenowska, elektryczność
Abstract in EnglishThe structural and electrical properties of new oxide ionic conductor BIMGVOX (Bi4Mg2xV22xOll-3x) have been investigated. The characterisation of structure, carried out by means of Xray and neutron powder diffraction, allowed to determine symmetry and lattice parameters as a function of the composition of studied material. Several compositionally and thermally dependent structural polymorphs have been detected (orthorhombic a i p, tetragonal y i y'). It was shown that the stabilisation of tetragonal y phase at high (above 500°C) to lower temperatures takes place for composition range of 0.10 < x < 0.25. The electrical conductivity measurements have been carried out by a.c. impedance spectroscopy. The highest conductivity at low temperature region (1.54.10-3 Scm-l at 300°C) was achieved for x = 0.13 composition. To determine the conductivity mechanism of oxide ions in BIMGVOX the defect structure of oxide sublattice was studied. The obtained data allowed for the determination of the positions of different atoms and their occupancies in the crystal structure it was shown that conductivity of BIMGVOX is mainly affected by two factors: the oxide vacancies concentration and the extent of defect trapping effect.
Thesis file
Malys_Marcin_struktura.pdf 4.75 MB
Citation count*4 (2015-07-23)

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