Crystal growth and properties of AgGaTe2

Large, crack-free single crystals of AgGaTe2 were grown for the first time using the horizontal gradient freeze technique. As-grown samples were trans parent from 1.2 mu m to beyond 16 mu m (the spectrometer limit): they exhib ited near-theoretical transmission at long wavelengths, but in the near-inf rared transmission was limited by scattering from second-phase precipitates (much like AgGaSe2 and AgGaS2). Dilatometer measurements on oriented singl e crystal revealed severely anisotropic thermal expansion similar in sign a nd magnitude to that of the sulfide and selenide analogs, Preliminary refra ctive index data suggests that the birefringence of AgGaTe2 may be slightly too small For phase-matched frequency conversion, but additional measureme nts over a broader wavelength range are required to refine the Sellmeier fi ts. (C) 2000 Elsevier Science B.V. All rights reserved.