X-RAY DIFFRACTION STUDIES OF THERMAL MOTIONS IN CRYSTALS

Abstract

Research continued on the general study, primarily by x-ray intensity-vs-temperature (I vs T) measurements, of thermal motions in crystals and their interaction with other phenomena of interest in crystal physics. Critical re-exa ination of experimental techniques led to a better understanding of background intensities and subsequently to the solution of several persistent problems. A graphical method (curvature method) developed for comparing the temperature dependence of the normalized temperature slope of log I vs T, A(T), with the theoretical prediction, f(x), by means of log-log plots. Results indicate that the curvature method is sensitive to discrepancies between experimental observations and theory, and that the Debye-Waller theory does not adequately describe the temperature dependence of Bragg intensities for AgCl. Thermal expansion data for AgCl, NaCl, and Al in the 100 K to 300 K temperature range were obtained. The discrepancies found between theory and experiment indicate a breakdown in the simplified MieGruneisen thermal expansion theory used, or the Debye lattice vibration theory, or both, for AgCl. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 31, 1961
Accession Number
AD0271421

Entities

People

  • R.a. Young
  • R.m. Nicklow

Organizations

  • Georgia Tech

Tags

DTIC Thesaurus Topics

  • Crystal Lattice Vibrations
  • Crystal Lattices
  • Curvature
  • Diffraction
  • Geometry
  • Intensity
  • Measurement
  • Observation
  • Thermal Expansion
  • Vibration
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Physics

Readers

  • Approximation Theory.
  • Materials Science and Engineering.
  • Theoretical Analysis.