Invited Review Paper

Optical Review

, Volume 14, Issue 1, pp 1-13

First online:

Influence of the Grain Boundaries on the Heat Transfer in Laser Ceramics

  • Jean-Francois BissonAffiliated withInstitute for Laser Science, University of Electro-Communications Email author 
  • , Hideki YagiAffiliated withInstitute for Laser Science, University of Electro-CommunicationsTakuma Works, Konoshima Chemical Co., Ltd.
  • , Takakimi YanagitaniAffiliated withTakuma Works, Konoshima Chemical Co., Ltd.
  • , Alexander KaminskiiAffiliated withInstitute of Crystallography, Russian Academy of Sciences, Crystal Laser Physics Laboratory
  • , Yuri N. BarabanenkovAffiliated withInstitute of Radio Engineering and Electronics, Russian Academy of Sciences
  • , Ken-Ichi UedaAffiliated withInstitute for Laser Science, University of Electro-Communications

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Grain boundaries play a key role in determining several key properties of polycrystalline laser ceramics. Heat transfer measurements at low temperature constitute a good tool to probe grain boundaries. We review the results of heat transfer measurements in polycrystalline Y3Al5O12 garnets as well as Y2O3 and Lu2O3 sesquioxide materials obtained by self-energy-driven sintering of nano-particles. The average phonon mean free path in Y3Al5O12 was found to be significantly larger than the average grain size and to scale with temperature as T −2 at low temperature. Existing models describing the interaction between phonons and grain boundaries are reviewed. Correct temperature dependence of the mean free path and order of magnitude of scattering rates were found by assuming the existence of a grain boundary layer having acoustic properties different from those of the bulk. A different temperature dependence of phonon mean free path was found for the sesquioxides and was ascribed to the stronger elastic anisotropy of these materials. The thermal resistance associated to the grain boundaries of laser ceramics was found to be lower than in other dense polycrystalline ceramic materials reported in the literature.

Key words

laser ceramics garnets sesquioxides grain boundaries thermal conductivity phonons