Author Type

Graduate Student

Date of Award

2002

Document Type

Thesis

Publication Status

Version of Record

Submission Date

October 2026

Abstract

Neutron powder diffraction, high pressure, magnetic susceptibility, and heat capacity measurements, as well as x-ray powder diffraction and iodometric titration, have been conducted on transition metal nickel oxides (TMOs), representative Ruddlesden-Popper (RP) phases Lan+1NinO3n+1 (n = 1, 2, ..., infinity) and hole-doped La2-xSr xNiO4 (0 < x < 1.2). The first complete study of La 2-xSrxNiO4 (0 < x < 1.2) and La n+1NinO3n+1 (n = 2 and 3) phases under high pressure is produced. Strong direct experimental evidence for polaron dominated electrical conduction in these charge transfer (CT) gap La2-xSr xNiO4 compounds is provided. Temperature evolution of the crystal structure of La2-xSrxNiO4 (x = 1/4 and 1/3) is revealed through neutron powder diffraction, structural relationships among n = 1, 2, and 3 phases are exhibited, and charge density wave (CDW) in multilayer Lan+1NinO3n+1 phases is strongly suggested. No superconductivity is observed at pressures up to 1.6 GPa and temperatures down to 4.2 K.

Extent

166 p.

Comments

FAU Electronic Theses and Dissertations Collection|Adviser: John J. Neumeier.|Thesis (Ph.D.)--Florida Atlantic University, 2002.|FAU Electronic Theses and Dissertations Collection

Identifier

FADT11997

Format

pdf

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