The X-ray Debye temperature of solid krypton

"Measurements of integrated intensities of X-ray Bragg reflections have been made as a function of temperature on two large single crystal specimens of solid krypton. These data have been interpreted in terms of a Debye characteristic temperature, 8 M "" according to the method suggested by Nicklow and Young. The specimens were prepared and maintained in a specially designed and constructed rigid-tail liquid helium cryostat and the measurements were made with a fourcircle X-ray diffractometer designed for use with this cryostat. The values of 8M, obtained in this work show a general qualitative agreement with existing quasi-harmonic and anharmonic theories, but suggest that further refinement is needed in the anharmonic theories. These results are also in general agreement with other thermodynamic data on solid krypton obtained by a diversity of experiments, including heat capacity measurements, vapor pressure measurements, entropy measurements, and neutron phonon dispersion measurements. On the other hand, the results of the present experiment disagree sharply with two previous experiments based on the Mossbauereffect, implying that there was some difficulty inherent in the Mossbauer methods. The high and low temperature expansions of 8M, in the harmonic approximation have been obtained showing that the high- and low-temperature limiting values of 8M, in this approximation are 8(-2) and 8(-3), respectively. The experimental value of 8(-2) obtained by this work is 67 +.5 K."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Windecker, Richard Chase

Contributors dc:contributor

• Simmons, R.O.

• x-ray debye temperature
• solid krypton
• x-ray Bragg reflections

Statement dc:rights

• 1970 Richard Chase Windecker

Language dc:language

en

Identifier

6031827

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25860