2002/09/26 by I. -K. Jeong, I.-K. Jeong, R. H. Heffner +3 · 3 citations
Chemistry · Earth and Planetary Sciences · Materials Science · Physics and Astronomy · #Atomic physics #Chemistry #Condensed matter physics #Debye #Debye function #Debye length #Debye model #Distribution function #High-pressure geophysics and materials #Interatomic potential #Ion #Lattice (music) #Microstructure and mechanical properties #Molecular dynamics #Molecular physics #Pair distribution function #Pair potential #Physics #Quantum mechanics #Radial distribution function #Thermodynamics #Vibration #X-ray Diffraction in Crystallography #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.67.104301
9 pages, 11 figures
arxiv created 2002/09/26 · openalex publication_date 2003/03/18 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The mean-square relative displacements (MSRD) of atomic pair motions in crystals are studied as a function of pair distance and temperature using the atomic pair distribution function (PDF). The effects of the lattice vibrations on the PDF peak widths are modelled using both a multi-parameter Born--von Karman (BvK) force model and a single-parameter Debye model. These results are compared to experimentally determined PDFs. We find that the near-neighbor atomic motions are strongly correlated, and that the extent of this correlation depends both on the interatomic interactions and crystal structure. These results suggest that proper account of the lattice vibrational effects on the PDF peak width is important in extracting information on static disorder in a disordered system such as an alloy. Good agreement is obtained between the BvK model calculations of PDF peak widths and the experimentally determined peak widths. The Debye model successfully explains the average, though not detailed, natures of the MSRDs of atomic pair motion with just one parameter. Also the temperature dependence of the Debye model largely agrees with the BvK model predictions. Therefore, the Debye model provides a simple description of the effects of lattice vibrations on the PDF peak widths.