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High‐Pressure Phase Behavior of Alumina: Predictions of a Transferable Ionic Potential Model
Author(s) -
Wilson Mark
Publication year - 1998
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1998.tb02661.x
Subject(s) - corundum , relaxation (psychology) , ab initio , phase transition , stoichiometry , dipole , ionic bonding , phase (matter) , thermodynamics , materials science , chemical physics , range (aeronautics) , ab initio quantum chemistry methods , ground state , oxide , chemistry , ion , mineralogy , molecule , atomic physics , physics , composite material , psychology , social psychology , organic chemistry , metallurgy
A recently introduced potential model for alumina has been used to study a wider range of structures than previously attempted. The model contains both the spherical relaxation of, and induced dipoles and quadrupoles on, the oxide anions. The model is applied to the possible high‐pressure phase transition from the ground‐state corundum structure to the Rh 2 O 3 ‐II structure. A transition pressure of 194 GPa has been predicted, which is in excellent agreement with the most‐recent experimental results. The spherical relaxation and induced quadrupoles are crucial in effectively modeling the transition. The shortcomings of the model are assessed by comparison with experiment and both ab initio and model calculations. Other structures common in this stoichiometry have also been considered.