A study of the structure and scattering mechanisms of subterahertz phonons in lithium fluoride single crystals and optical ceramics

Journal Article · Tue Jun 15 04:00:00 EDT 2010 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776110060087· OSTI ID:21443503

Gainutdinov, R V; Akchurin, M Sh ^[1]; Basiev, T T; Konyushkin, V A; Fedorov, P P; Kuznetsov, S V; Osiko, V V ^[2]

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1. Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)
2. Russian Academy of Sciences, Research Center of Laser Materials and Technologies, Prokhorov General Physics Institute (Russian Federation)

The methods of optical, electron, and atomic force microscopy (AFM) are applied to the study of the real structure of optical lithium fluoride ceramic obtained by hot deformation of single crystals. A comparative analysis is carried out of the scattering mechanisms of weakly nonequilibrium thermal phonons at liquid helium temperatures in LiF single crystals and ceramics. It is demonstrated that the phonon scattering in the original single crystals is determined by the forced vibrations of dislocations in the stress field of an elastic plane wave (a phonon), i.e., by the flutter mechanism. As the degree of deformation of the original material increases, the ceramics exhibit a change in the plastic deformation mechanisms, which leads to a decrease in the average size of grains and to an ordered structure. In this case, the dominant scattering is that by intergrain boundaries. The thickness and the acoustic impedance of these boundaries are evaluated.

• OSTI ID: 21443503
• Journal Information: Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 6 Vol. 110; ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALI METAL COMPOUNDS
ATOMIC FORCE MICROSCOPY
CERAMICS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DEFORMATION
DISLOCATIONS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
IMPEDANCE
LINE DEFECTS
LITHIUM COMPOUNDS
LITHIUM FLUORIDES
LITHIUM HALIDES
MECHANICAL PROPERTIES
MICROSCOPY
MONOCRYSTALS
PHONONS
PLASTICITY
QUASI PARTICLES
SCATTERING
STRESSES
TEMPERATURE RANGE
TEMPERATURE RANGE 0000-0013 K
WAVE PROPAGATION