Nuclear magnetic resonance investigations of structural phase transitions in silicon dioxide cristobalite and tridymite and related phases

This thesis contributes to the application of nuclear magnetic resonance (NMR) techniques in studying structural phase transitions (SPT's) of the SiO$\sb2$ cristobalite and SiO$\sb2$ and AlPO$\sb4$ tridymite polymorphs. The structural properties and SPT's of these phases have been of mineralogical, physical and industrial interest for decades. However, the microscopic characteristics of the SPT's and the origins of the commonly observed structural disorder in the high temperature phases have been poorly known. NMR techniques call provide important information concerning the temperature variation of the short-range structural parameters through SPT's. Moreover, the dynamical behavior of high temperature phases in the NMR frequency range ($\sim$1-500 MHz) can sometimes be uniquely elucidated by relaxation rate measurements and spectral simulation. The work presented here includes in situ high temperature $\sp{29}$Si, $\sp{31}$P and $\sp{27}$Al NMR results for cristobalite (Chapter II), chemically stabilized β-cristobalite (Chapter III), various tridymite polymorphs (MC and PO, Chapter IV; MX-1 Chapter V; AlPO$\sb4,$ Chapter VI) and a spin-lattice relaxation investigation of the dynamic properties for the high temperature SiO$\sb2$ and AlPO$\sb4$ tridymite phases (Chapter VII).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Geology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Xiao, Yuehui

Contributors dc:contributor

• Kirkpatrick, R. James

• Mineralogy
• Chemistry, Inorganic
• Physics, Condensed Matter

Statement dc:rights

• Copyright 1994 Xiao, Yuehui

Language dc:language

eng

Identifier

AAI9512603
(UMI)AAI9512603

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21128