Molecular-Dynamics Simulations of Some BaXF₄ Compounds

Authors

John Flocken, University of Nebraska at Omaha, Omaha, Nebraska
Z. Mo, University of Nebraska at Omaha, Omaha, Nebraska
Wai-Ning Mei, University of Nebraska at OmahaFollow
John R. Hardy, University of Nebraska - LincolnFollow
Dorian Hatch, Brigham Young University, Provo, Utah

Date of this Version

1994

Comments

Published in Phys. Rev. B 49, 5811 - 5816 (1994). Copyright © 1994 The American Physical Society. Used by permission.

Abstract

We have carried out molecular-dynamics simulations on BaXF₄ compounds, where X is Mg, Mn, or Zn. Ab initio potentials, with no adjustable parameters, were used to obtain short-range interactions between ion pairs. We found a polar ground-state structure which is in agreement with the A2₁am space group reported experimentally. We were able to reverse polarization in BaMgF₄ at high temperatures, using large fields, but were unable to reverse polarization in the other compounds. The second-order phase transition in the Mn compound at 250 K was reproduced. We believe this to be the first extension of molecular dynamics to materials consisting of chains of F octahedra.