Crystal Growth and Glass-Like Thermal Conductivity of Ca3RE2(BO3)4 (RE = Y, Gd, Nd) Single Crystals

Abstract

Abstract:Crystal growth and thermal properties of binary borates, Ca 3 RE 2 (BO 3 ) 4 (RE = Y, Gd, Nd), are considered promising crystals for laser applications. These single crystals were grown by the Czochralski method. The crystal and defect structure were characterized. Volumetric chemical methods without prior separation of the components were developed and applied for the determination of the dependence of chemical compositions of the crystals on the growth conditions. The thermal conductivity was investigated in the 50-300 K range. The character of the temperature dependence of thermal conductivity was found to be similar to that of glass. The possible reasons of the observed features of the thermal conductivity were analyzed.

Variation of cation distribution with temperature and its consequences on thermal expansion for Ca3Eu2(BO3)4

“…Multistage solid-state synthesis, based on step decomposition of calcium carbonate and boric acid, was developed for production of pure and doped Ca 3 RE 2 (BO 3 ) 4 (RE = Y, Gd) compounds (Gudzenko, Kosmyna, Radchenko et al, 2017). This approach was applied for the Ca 3 Eu 2 (BO 3 ) 4 synthesis.…”

SESAM Mode-Locked Yb:Ca3Gd2(BO3)4 Femtosecond Laser

“…In the GdCB structure, the Ca 2+ and Gd 3+ cations statistically occupy three non-equivalent crystallographic sites, forming M-oxygen distorted polyhedrons [17] (the dopant Yb 3+ ions are expected to replace the Gd 3+ ones). This leads to a "glassy-like" spectroscopic behaviour of Yb:GdCB crystals at the expense of a relatively low thermal conductivity of 0.92 W/mK at room temperature [18]. It features an extremely broad, flat and smooth gain profile which is very suitable for ultrafast pulse generation from a mode-locked laser.…”

Flow Instabilities of Coupled Rotation and Thermal-Solutal Capillary Convection of Binary Mixture in Czochralski Configuration

“…Especially, under microgravity conditions, the effect of gravity is minimized [5] and the effect of thermal-solutal capillary flow generated by surface tension gradient is highlighted [6][7][8]. Czochralski (Cz) crystal growth technology is an important method for producing crystals, where a rod-mounted seed crystal dipped into melt and carefully pulled out by controlling the thermal and concentration gradients, crystal rotation and pulling rates [9,10]. Thus, the thermal-solutal capillary forces generated by the surface tension gradient, the centrifugal and Coriolis forces induced by rotation are coupled and make the flow become very complex.…”