Thermal properties of monoclinic KLu(WO4)2 as a promising-solid state laser host

Identificador:  imarina:6385697

Handle: https://hdl.handle.net/20.500.11797/imarina6385697

Autors:  Silvestre, Oscar; Grau, Joan; Pujol, Maria Cinta; Massons, Jaume; Aguilo, Magdalena; Diaz, Francesc; Borowiec, Mieczyslaw Tadeusz; Szewczyk, Andrzej; Massot, Marta; Salazar, Agustin; Petrov, Valentin

Resum:
Thermal analysis of the monoclinic solid state laser host KLu(WO 4)2 is presented. The specific heat was measured by the relaxation method in the temperature range from 1.9 to 385 K: its value at room temperature is 0.324 J/gK. The Debye temperature and the sound velocity amount to 303±3 K and 3734 m/s. The linear thermal expansion tensor was measured by X-ray powder diffraction from room temperature up to 773 K. The eigenvalues of this tensor are α'11=8.98×10-6 K -1, α'22=3.35×10-6K-1, and α'33=16.72×10-6 K-1, with the maximum value in the a-b crystallographic plane, at 31.94° from the N g principal optical axis. The thermal diffusivity and its anisotropy in the temperature range between 300 and 500 K were measured by the pyroelectric method to determine the thermal conductivity tensor. The eigenvalues of the thermal conductivity are κ'11=2.95 Wm-1K -1, κ'22=2.36 Wm-1K-1, and κ'33=4.06 Wm-1K-1, with the maximum value along a direction again in the a-b crystallographic plane, at 40.75° from the Ng principal optical axis. Simulation of the temperature distribution in a bulk sample of KLu(WO4)2 with dimensions 3×3×3 mm3 shows that pump and laser beam directions along the N p principal optical axis in terms of thermal effects are preferable because the propagation is along a quasi-isothermal path. © 2008 Optical Society of America.