摘要/詳細資料

Magnetostructural correlations in cylindrite-based materials

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

摘要 (摘要)

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.

索引 (詳細資料)


主題
Materials science
分類
0794: Materials science
識別碼/關鍵字
Applied sciences; Cylindrite; Magnetostructural
標題
Magnetostructural correlations in cylindrite-based materials
作者
Salyer, Pamela A.
頁數
342
學位日期
1999
學校代碼
0459
來源
DAI-B 61/02, Dissertation Abstracts International
出版地
Ann Arbor
出版國家/地區
United States
ISBN
978-0-599-63228-8
指導者
Haar, Leonard W. ter
大學/機構
The University of Texas at El Paso
大學地點
United States -- Texas
學位
Ph.D.
來源類型
論文或專題
語言
英文
文件類型
Dissertation/Thesis
論文/專題編號
9959918
ProQuest 文件識別碼
304549962
著作權
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/unauthdocview/304549962