Crystal-field induced dipoles in heteropolar crystals I: Concept

  title={Crystal-field induced dipoles in heteropolar crystals I: Concept},
  author={M. Birkholz},
  journal={Zeitschrift f{\"u}r Physik B Condensed Matter},
  • M. Birkholz
  • Published 1995
  • Physics
  • Zeitschrift für Physik B Condensed Matter
The electrostatic part of the internal energy of heteropolar crystals is largely assumed to be purely of the Coulomb or monopole type. Here, it is argued, ions in a crystal lattice may not only bear a net charge, but also higher electrostatic moments. This applies explicitly for dipole moments. Dipoles are assumed to occur only for ions on lattice sites where the point symmetry allows a non-vanishing crystal electric field to cause a polarization. Infinite lattice sums that account for the… Expand
19 Citations
Crystal-field induced dipoles in heteropolar crystals II: Physical significance
The significance of dipole moments induced by crystal fields in heteropolar crystals is discussed with respect to some aspects of solid state physics. Experimental results from structural analysesExpand
Modeling the Shape of Ions in Pyrite-Type Crystals
The geometrical shape of ions in crystals and the concept of ionic radii are re-considered. The re-investigation is motivated by the fact that a spherical modelling is justified for p valence shellExpand
Electrostatic lattice coefficients and binding energy of orthorhombic La2-xSrxCuO4
Three valency models for orthorhombic La2-xSrxCuO4 were investigated for increasing Sr concentrationsx (0≤x≤0.21): 1. Cu2+→Cu3+, 2. apex O2−→O− and 3. in-plane O2−→O−. All calculations were done byExpand
Variations of ionic binding energies and the distribution of charge carriers in orthorhombic La2−xSrxCuO4
The significance of heterovalent, substitutional disorder for the distribution of charge carriers in La2−xSrxCuO4 has been investigated. Disorder is shown to cause strong variations of bindingExpand
Interatomic distances in pyrite‐structure disulfides – a case for ellipsoidal modeling of sulfur ions
The geometry of crystalline bonding in pyrite-structure disulfides MS2 is investigated for the M = Mn, Fe, Co, Ni, Cu series. The decomposition of interatomic distances by the ionic radii approach isExpand
Single-Molecule Piezoelectric Deformation: Rational Design from First-Principles Calculations
Conventional piezoelectric materials change shape in response to an applied external electric field, frequently deforming at grain boundaries in addition to intrinsic unit cell changes. We detail aExpand
Evidence of linear lattice expansion and covalency enhancement in rutile TiO2 nanocrystals
Lattice variations and bonding characteristics in rutile TiO2 nanocrystals were examined by x-ray diffraction and x-ray photoelectron spectroscopy. With a reduction in the physical dimensions, rutileExpand
The effect of nanocrystallite size in monoclinic HfO2 films on lattice expansion and near-edge optical absorption
Nanocrystalline monoclinic HfO2 films were sputter deposited on fused silica substrates, air annealed at 573 to 1273 K to affect crystallite growth, and analyzed by x-ray diffraction andExpand
Surface enhanced covalency and Madelung potentials in Nb doped SrTiO3 (100), (110) and (111) single crystals
The influence of surface enhanced covalency on the Madelung potential is experimentally investigated using angle-resolved photoemission for (100), (110) and (111) SrTiO3 surfaces after annealing inExpand
Enhanced electrical properties in Rb-substituted sodium bismuth titanate ceramics
Influence of large ionic radius cation rubidium (Rb) substitution in the A-site of sodium bismuth titanate (NBT) on remnant polarization and dielectric constant is investigated. Substitution of 0.01Expand


Crystal-field induced dipoles in heteropolar crystals II: Physical significance
The significance of dipole moments induced by crystal fields in heteropolar crystals is discussed with respect to some aspects of solid state physics. Experimental results from structural analysesExpand
The crystal energy of pyrite
The crystal energy of iron pyrite, ideally of composition FeS2, is evaluated with an ionic model, assuming atoms in the solid to be ionized as Fe2+ and S-. To calculate the proper crystal energy,Expand
Effects of atomic polarization in ionic crystals
The effect of higher order atomic polarizations on the cohesive energy of ionic crystals is treated on the basis of a model according to which the crystal consists of polarizable non-overlappingExpand
Methods of Calculating the Crystalline Electric Field
Two convenient methods are developed for calculating the coefficients of expansion of the crystalline potential in spherical harmonics. One consists in extending Evjen's elementary method ofExpand
The lattice contribution to the field gradient in ionic crystals and metals may be evaluated by breaking the field gradient up into a number of conditionally convergent series with poor convergence,Expand
Crystalline Fields in Corundum‐Type Lattices
Dipole moments of the deformable O2— ions in the corundum‐type crystals Al2O3, Cr2O3, and Fe2O3 are calculated self‐consistently. The magnitudes and signs of the dipole moments depend sensitively onExpand
The electrostatic potential in multipole lattices
Synopsis General expressions for the electrostatic potential in perfect multipole lattices are given as expansions in terms of spherical harmonics. The coefficients occurring in these expansionsExpand
Crystal symmetry and physical properties: application of group theory
The paper gives a brief account of group-theoretical methods of studying the effect of symmetry on all possible physical properties (known and already measured or not known) which depend on crystalExpand
Nuclear Quadrupole Interactions in Beryllium Oxide
The importance of the contribution from higher multipole moments of oxygen ions to the electric field gradient at nuclei in a wurtzite-type ionic oxide, namely, beryllium oxide, is considered and, inExpand
Anion dipole contribution to the lattice energy of rutile
Permanently polarized anions in crystals possessing the rutile structure contribute extra terms to the lattice energy of such crystals. The dipole term has been calculated for TiO2 and estimated forExpand