Self-consistent tight-binding approximation including polarisable ions

TY - JOUR

T1 - Self-consistent tight-binding approximation including polarisable ions

AU - Finnis, M.W.

AU - Paxton, A.T.

AU - Methfessel, M.

AU - van Schilfgaarde, M.

N1 - cited By (since 1996) 3; Conference of Proceedings of the 1997 MRS Fall Symposium; Conference Date: 1 December 1997 through 3 December 1997; Conference Code: 48274

PY - 1998

Y1 - 1998

N2 - Until recently, tight-binding has been applied to either covalent or metallic solid state systems, or charge transfer treated in a simple point charge framework. We present a self-consistent tight-binding model which, for the first time, includes electrostatic ion polarisability and crystal field splitting. The tight-binding eigenvectors are used to construct multipole moments of the ionic charges which are used to obtain angular momentum components of the electrostatic potential in structure constant expansions. Our first test of the model is to study the phase stability in zirconia; in particular the instability of the fluorite phase to a spontaneous symmetry breaking, and its interpretation in terms of band effects and ion polarisability. This new formalism opens up the way to apply the tight-binding approximation to problems in which polarisation of atomic charges is important, for example oxides and other ceramic materials and surfaces of metals.

AB - Until recently, tight-binding has been applied to either covalent or metallic solid state systems, or charge transfer treated in a simple point charge framework. We present a self-consistent tight-binding model which, for the first time, includes electrostatic ion polarisability and crystal field splitting. The tight-binding eigenvectors are used to construct multipole moments of the ionic charges which are used to obtain angular momentum components of the electrostatic potential in structure constant expansions. Our first test of the model is to study the phase stability in zirconia; in particular the instability of the fluorite phase to a spontaneous symmetry breaking, and its interpretation in terms of band effects and ion polarisability. This new formalism opens up the way to apply the tight-binding approximation to problems in which polarisation of atomic charges is important, for example oxides and other ceramic materials and surfaces of metals.

KW - Ions

KW - Metals

KW - Mathematical models

KW - Ceramic materials

KW - Zirconia, Crystal field splitting

KW - Self consistent tight binding approximation, Materials science

KW - Stability

KW - Electrostatic ion polarisability

KW - Polarisable ions

KW - Fluorine compounds

KW - Eigenvalues and eigenfunctions

KW - Surfaces

KW - Approximation theory

KW - Oxides

M3 - Conference paper

VL - 491

SP - 265

EP - 274

JO - Materials Research Society Symposium Proceedings

JF - Materials Research Society Symposium Proceedings

T2 - Symposium on Materials Science of the Cell at the 1997 MRS Fall Meeting

Y2 - 1 December 1997 through 4 December 1997

ER -