Resumo/Detalhes

Magnetostructural correlations in cylindrite-based materials

Salyer, Pamela A.   The University of Texas at El Paso ProQuest Dissertations Publishing,  1999. 9959918.

Resumo (sumário)

The mineral cylindrite (nominal composition FePb3Sn4 Sb2S14) is a layered chalcogenide with an unusual cylindrical morphology that occupies an important role in the search for new magnetic materials. The primary aim of this project is to characterize the magnetic properties of cylindrite, and to use the characterization to understand its structural and compositional variances. Due to its inherent curvature and incommensurate sublattices, the structure of cylindrite has historically proven difficult to solve, and the exact atomic positions are unknown. This work capitalizes on cylindrite's Fe content as a unique opportunity to further understand its structure and composition through magnetism. Magnetic investigations (both powder and single crystal) have been carried out on four separate specimens of cylindrite. The magnetic ion is confirmed as a six-coordinate, Fe +2, d6 ion with a high spin (S = 2) ground state of t2g 4eg2. Temperature dependent susceptibility (χ vs. T) studies reveal differences in magnetic behavior that can be attributed to cylinder aspect ratio (i.e., length/diameter = 2−10). Notably, a correlation between the cylinder aspect ratio and the magnetic anisotropy below 60 K is attributed to the chemistry of Fe+2 in cylindrite's lattice. A scheme invoking crystallographic relationships similar in concept to anti-ferrodistortive ordering enables the single-ion anisotropies (χ// and χ) for the Fe+2 ions in cylindrite to be deduced from the calculated average magnetic susceptibility (χavg). The magnetic studies, in combination with compositional analyses (i.e., Energy-Dispersive Spectrometry (EDS), Wavelength-Dispersive Spectrometry (WDS)) have led to several magnetostructural correlations and the proposal of a magnetic model for cylindrite-based structures.

Indexação (detalhes)


Assunto
Materials science
Classificação
0794: Materials science
Identificador / palavra-chave
Applied sciences; Cylindrite; Magnetostructural
Título
Magnetostructural correlations in cylindrite-based materials
Autor
Salyer, Pamela A.
Número de páginas
342
Data da graduação
1999
Código da escola
0459
Fonte
DAI-B 61/02, Dissertation Abstracts International
Local de publicação
Ann Arbor
País de publicação
United States
ISBN
978-0-599-63228-8
Orientador
Haar, Leonard W. ter
Universidade/instituição
The University of Texas at El Paso
Localização da universidade
United States -- Texas
Licenciatura
Ph.D.
Tipo de fonte
Dissertação ou tese
Idioma
Inglês
Tipo de documento
Dissertation/Thesis
Número da dissertação/tese
9959918
ID do documento da ProQuest
304549962
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/unauthdocview/304549962