Author Type

Graduate Student

Date of Award

2005

Document Type

Thesis

Publication Status

Version of Record

Submission Date

October 2026

Abstract

Magnetic, thermodynamic, and structural properties of the manganese oxides La1-xCa xMnO3 are studied. Neutron powder diffraction reveals two distinct crystallographic phases as well as two magnetic (ferromagnetic and antiferromagnetic) phases for 0.08 < x < 0.14. Details of the compositional dependence of the phase fractions is discussed in the context of local ferromagnetism. Comparisons of magnetic and crystallographic properties are made to the analogous electron-doped Ca1- yLayMnO3 (0 < y < 0.20) system. Thermodynamic properties of La1- xCaxMnO 3 (0 < x < 0.54) are investigated for possible applications in magnetic refrigeration. A maximum magnetic entropy change of 5.5 J/kg K and a corresponding temperature change of 2 K are estimated for x = 0.28. The magnetocaloric effect in antiferromagnetic and charge-ordering compounds is found to be small.

Extent

122 p.

Comments

FAU Electronic Theses and Dissertations Collection|Adviser: John J. Neumeier.|Thesis (Ph.D.)--Florida Atlantic University, 2005.|FAU Electronic Theses and Dissertations Collection

Identifier

FADT12133

Format

pdf

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