Volume 68, Number 4, November 2004
|Page(s)||550 - 556|
|Section||Condensed matter: structure, mechanical and thermal properties|
|Published online||29 October 2004|
Strain-induced disorder and phase transformation in hexagonal boron nitride under quasi-homogeneous pressure: In situ X-ray study in a rotational diamond anvil cell
Texas Tech University, Center for Mechanochemistry and Synthesis of New Materials, Department of Mechanical Engineering Lubbock, TX 79409-1021, USA
Accepted: 17 September 2004
One of the challenges in characterization of strain-induced transformations is to create uniform pressure. In this letter, conditions for nearly homogeneous pressure distribution are predicted and achieved experimentally. Compared to hydrostatic loading, plastic shear generally reduces the transformation pressure significantly. We observed, however, an unexpected phenomenon: the transformation of hexagonal to superhard wurtzitic BN under pressure and shear initiated at a pressure comparable to that in hydrostatic compression (). In situ X-ray diffraction revealed that plastic shear increases the disorder, while hydrostatic compression does not. This increase neutralizes the transition pressure reduction caused by shear. For the same disorder, shear reduced the transformation pressure significantly, and caused a complete, irreversible transformation.
PACS: 64.60.-i – General studies of phase transitions / 64.70.Kb – Solid-solid transitions
© EDP Sciences, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.