Thermal Conductivity, Diffusivity, and Expansion of Y2O3, Y3 Al5O12, and LaF3 in the Range 77°–300°K

Abstract

The thermal conductivities of Y2O3, Y2O3:Nd3+, Y3Al5O12:Nd3+, and LaF3 have been measured from 77°–300°K by a steady-heat-flow method. The densities of these crystals and of LaF3:Nd3+ have been determined in the same temperature range, using x-ray methods. Using this information and specific heat data from a variety of sources, the thermal diffusivities of these materials have been calculated. Although the diffusivity of pure yttrium oxide is somewhat higher than that of pure yttrium aluminum garnet, introduction of about 1 mole % of neodymium into both these compounds leads to crystals with diffusivities approximating that of undoped YAG. The diffusivity of doped yttrium oxide and YAG (about 0.05–0.06 cm2/sec at room temperature) is about three times that found for undoped lanthanum fluoride. The relative ease with which heat may be removed from Nd-doped Y2O3 and YAG suggests their use in lasers to diminish time variations in the width of the beam.

Influence of Temperature on Refractive Indices of BaLaGa3O7and SrLaGa3O7

“…(7) and the relevant material constants. With reported data for YAG:Nd -K = 0.13 W/cm K [7], dn/dT = 7.3 x 10 -6 K-1 [8] and for BLGO:Nd -K = 0.11 W/cm K [4], dn/dT = 2 x 10 -5 K-1 the expected focal length of . thermally induced lens is shorter in BLGO:Nd by a factor of three than in YAG:Nd.…”

A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.

“…The particle's thermal response time was evaluated using Konopliv and Sparrow's analytical solutions for a 1-D, transient conduction heat transfer model [30] of a spherical particle at an initial temperature (T p0 ) surrounded by an infinite gas with a uniform temperature (T ∞ ). The thermal properties of BAM are currently not well characterized and therefore thermal properties of YAG were used in the model [31]. The model assumes a uniform temperature for the particle since its thermal conductivity (k p ) is several orders of magnitude greater than the surrounding gas.…”

Efficient, low threshold, cryogenic Ho:YAG laser

“…This substantially reduces the pump intensity required to achieve transparency and reach laser threshold. Furthermore, operating at CTs dramatically increases the thermal conductivity and decreases both the thermal expansion coefficient and dn/dT in the crystalline YAG host [12][13][14]. Several liquid nitrogen (LN) cooled Yb:YAG lasers have demonstrated these advantages with high average power and good beam quality using disk [15], rod [16] and slab [17] gain media.…”