Growth, optical and thermal properties of YbxHo1-xCa4O(BO3)3 crystals

YbxHo1-xCa4O(BO3)3 (Yb:HoCOB, x = 0, 0.1, 0.2, 0.3) crystals were grown by the Bridgman method for the first time. The crystal structure, rocking curve, transmission spectra, absorption spectra, band structure and thermal properties of Yb:HoCOB were characterized in detail. The maximum half peak width (FMHW) of Yb0.1Ho0.9COB and Yb0.2Ho0.8COB is 26.7″ and 23.8″, respectively, and the effective segregation coefficient is greater than 0.9. In addition, the transmittance of Yb:HoCOB is 88 %. New absorption peaks are introduced by doping Yb3+ at 850–1000 nm. The UV absorption cut-off edge of Yb:HoCOB is red-shifted with increasing Yb3+ doping. The thermal diffusivity and thermal conductivity of Yb:HoCOB decrease with increasing temperature. The specific heat increases with the increasing temperature and finally approaches a constant value. The specific heat of Yb:HoCOB crystal are above 0.670 J/gK at room temperature. Yb:HoCOB with good crystallization quality, high transmittance and high specific heat has the application potential in laser frequency and QPCPA. This work provides a useful exploration for the study of nonlinear optical materials in solid state lasers.