Theory of binding of ionic crystals: Application to alkali-halide and alkaline-earth-dihalide crystals

1974 ◽  
Vol 9 (8) ◽  
pp. 3548-3554 ◽  
Author(s):  
Yung Sik Kim ◽  
R. G. Gordon
Keyword(s):  
Alkali Halide ◽  
Alkaline Earth ◽  
Ionic Crystals

Frictional Force Microscopic Detection of Anisotropy and Asymmetry at Various Atom-Flat Surfaces

2005 ◽  
Author(s):  
Hitoshi Shindo ◽  
Sei-ichi Kondo ◽  
Kozo Shitagami ◽  
Takashi Sugai ◽  
Yoshimichi Namai ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Frictional Force ◽  
Alkali Halide ◽  
Adsorbed Water ◽  
Ionic Crystals ◽  
Surface Geometry ◽  
Flat Surfaces ◽  
Force Microscopy ◽  
Microscopic Detection ◽  
Mass Spring

Frictional force microscopy (FFM) was applied to the detection of frictional asymmetry due to molecular tilt, and anisotropy at various atom-flat surfaces of ionic crystals. Less tilted S=O bonds at CaSO4(100) face and more tilted C=O bonds at (10–14) face of calcite gave contrasting results of asymmetry, which are explained by describing the bonds as mass-spring systems. Frictional anisotropy arises from different periodicity of atoms depending upon the scan directions of the probe. Alkali halide surfaces showed anisotropy due to arrangement of electric charges. Surface geometry also causes anisotropy at corrugated CaSO4(001), etc. Adsorbed water can reduce or enhance friction depending upon the relative humidity and the nature of the surfaces.

A simple melting theory applied to alkali halide, alkaline-earth chalcogenide, and alkali chalco-genide compounds

2005 ◽  
Vol 83 (6) ◽  
pp. 653-660 ◽  
Author(s):  
Quan Liu ◽  
Li-rong Chen
Keyword(s):  
Melting Temperature ◽  
Potential Function ◽  
Alkali Halide ◽  
Alkaline Earth ◽  
Simple Method ◽  
Wide Range ◽  
64.70 Dv ◽  
Experimental Values

A useful and simple method for studying the melting temperature Tm of ion compounds has been developed by using analyses originally due to diffusional force theory, incorporating Pandey's formulation and Harrison's potential function. The calculated values of Tm for a wide range of compounds of types IA–VII (alkali halide), IIA–VI (alkaline-earth chalcogenide), and IA–VI (alkali chalcogenide) are found to agree fairly well with experimental values for Tm and to be superior to results from previous approaches involving similar methods. PACS Nos.: 64.70.Dv, 67.80.Gb

Hartree-Fock Cluster Computations for Ionic Crystals

1985 ◽  
Vol 63 ◽  
Author(s):  
J. M. Vail ◽  
R. Pandey
Keyword(s):  
Shell Model ◽  
Alkaline Earth ◽  
Optical Transition ◽  
Alkali Halides ◽  
Wave Functions ◽  
Ionic Crystals ◽  
Perfect Lattice ◽  
Hartree Fock ◽  
Quantum Cluster ◽  
Model Lattice

ABSTRACTThe ICECAP code is applied to charged and uncharged color centers in alkali halides and alkaline-earth oxides, to test the usefulness of complete-cation pseudopotentials for reproducing the cluster boundary conditions. The physical model includes consistency up to electrostatic octupole order between the Hartree-Fock cluster and the surrounding infinite shell-model lattice. The total energy of the system is determined variationally, including distortion and polarization of the cluster and lattice, and LCAO-MO gaussian-localized cluster wave functions. Electronic states with the lattice unrelaxed are also analysed, yielding color-center optical transition energies. Furthermore, consistency between quantum (cluster) and classical (shell-model) descriptions of the perfect lattice is tested.

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