Title page for ETD etd-06082009-171157

Type of Document Master's Thesis
Author Macey, Brett Jarrod
URN etd-06082009-171157
Title The crystal chemistry of MTO4 compounds with the zicron, scheelite, and monazite structure types
Degree Master of Science
Department Geological Sciences
Advisory Committee
Advisor Name Title
Ribbe, Paul H. Committee Chair
Bodnar, Robert J. Committee Member
Gibbs, Gerald V. Committee Member
  • structures
Date of Defense 1995-09-15
Availability unrestricted

The crystal structures of zircon, scheelite, and monazite are very closely related. All three have chains of alternating polyhedra and planes of closest packed or pseudoclosest packed cations. Using these similarities the unit cells of these structures can be placed in analogous orientations. This in turn leads to a better understanding of the geometrical aspects of the reconstructive phase transformations that occur among the structure types as functions of temperature and pressure. In essence the phase transformations require the cation planes of one structure to the cation planes of another. Phase transformations also occur via compositional pathways.

Crystal structure parameters were modeled for compounds with the Zlfcon, scheelite and monazite structure types using multiple regression techniques. Data consisted of structure refinements of 26 zircon-, 13 scheelite-, and 13 monazite-type compounds. These compounds include but are not limited to the lanthanide vanadates and phosphates, the alkali earth molybdates and tungstates, and KTc04. The structural parameters studied included bond lengths, bond angles, polyhedral volumes, unit cell edge lengths, tetrahedral quadratic elongations and atomic coordinates of individual atoms; they were modeled as a function of the Shannon radii of the cations and the product of the M and T cation charges. Correlation coefficients for these regressions exceeded 0.9 for nearly all parameters studied except for the y coordinate of M, the z coordinate of 0 1, and T -0 I-M2 angle of the monazite compounds.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  LD5655.V855_1995.M334.pdf 3.05 Mb 00:14:06 00:07:15 00:06:20 00:03:10 00:00:16
[BTD] next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.