Accession Number : AD0775211

Title :   Preparation and Single Crystal Growth of LiYF4 Laser Materials.

Descriptive Note : Final rept. 1 Jan-31 Dec 73,

Corporate Author : LITTON SYSTEMS INC MORRIS PLAINS N J LAMBDA-AIRTRON DIV

Personal Author(s) : Uhrin,Robert ; Belt,Roger F. ; Puttbach,Richard C. ; Kinloch,Durand R.

Report Date : FEB 1974

Pagination or Media Count : 37

Abstract : The report describes techniques for preparation of high purity fluorides suitable for laser crystal hosts. Growth methods for LiYF4 were also developed using a constant flow of HF. The YF3 and rare earth fluorides are prepared from 5 or 6-9's polycrystalline oxides. A special platinum reactor was designed to convert oxides to fluorides via an HF reaction. Trifluorides were prepared at 800-900C and melted under HF at 1050-1200C. This prevented formation of oxide and oxyfluoride impurities in the melt. Growth of LiYF4 was accomplished in a resistively heated platinum apparatus and crucible using a modified Czochralski method. Growth occurred under a fixed pressure of HF. Preliminary results gave crystals of high optical quality, free of OH(-), scattering sites, and low impurity level. The procedures should be applicable to other YLF materials in volume production. (Author)

Descriptors :   *Laser materials, *Lithium fluorides, *Crystal growth, Yttrium compounds, Fluorides, Single crystals, Chemical reactions, Phase diagrams

Subject Categories : Lasers and Masers
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE