Stability and Equation of State of a Nanocrystalline Ga-Ge Mullite in a Vitroceramic Composite: A Synchrotron X-ray Iffraction Study

Authors

Kristina E. Lipinska-Kalita, University of Nevada, Las VegasFollow
Patricia Kalita, University of Nevada, Las VegasFollow
Cedric Gobin, University of Nevada, Las Vegas
Oliver Hemmers, University of Nevada, Las VegasFollow
Thomas Hartmann, Harry Reid Center for Environmental StudiesFollow
Gino Mariotto, University of Verona, Faculty of Mathematical, Physical and Natural SciencesFollow

Document Type

Article

Publication Date

4-10-2008

Publication Title

Physical Review B

Publisher

American Physical Society

Volume

77

Issue

13

First page number:

134107-1

Last page number:

134107-8

Abstract

Synchrotron x-ray diffraction and diamond anvil cell techniques were used to characterize the phase transformations and to evaluate the structural stability at elevated pressures of a developed nanocrystalline composite. The optically transparent material was built of a germanium oxide-based amorphous host matrix with homogeneously dispersed 13±3 nm Ga-Ge mullite-type nanocrystals, which had a structure similar to the conventional Al₂O₃-SiO₂ mullite. The equation of state of the nanocrystals and the overall structural integrity of the nanocomposite were investigated in quasihydrostatic conditions on compression to 36 GPa and on the following decompression to ambient conditions. The overall pressure-induced changes of x-ray diffraction patterns evidenced that the structural integrity of the material is well preserved up to about 14–16 GPa. The nanocomposite decompressed from 36 GPa to ambient pressure showed a very limited reversibility of the pressure-driven changes. A Birch-Murnaghan fit of the unit cell volume as a function of pressure yielded a zero-pressure bulk modulus, K₀, for the nanocrystalline phase of 229(15) GPa which makes this material potentially interesting for structural applications at elevated pressures.

Controlled Subject

High pressure crystallography; Nanocomposites (Materials); Nanostructured materials

Disciplines

Biological and Chemical Physics | Materials Chemistry | Physical Chemistry

Language

English

Permissions

Copyright American Physical Society. Used with permission.

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Repository Citation

Lipinska-Kalita, K. E., Kalita, P., Gobin, C., Hemmers, O., Hartmann, T., Mariotto, G. (2008). Stability and Equation of State of a Nanocrystalline Ga-Ge Mullite in a Vitroceramic Composite: A Synchrotron X-ray Iffraction Study. Physical Review B, 77(13), 134107-1-134107-8.
https://digitalscholarship.unlv.edu/hrc_fac_articles/6