Crystal growth and thermal properties of single crystal monoclinic NdCOB (NdCa4O(BO3)3)

A new member of the RECa4O(BO3)3 crystal system, a neodymium calcium oxoborate [NdCa4O(BO3)3, abbreviated as NdCOB] single crystal, with dimensions of 30 mm in diameter and 25 mm in length, has been grown along the crystallographic b-axis by the Czochralski method. X-ray powder diffraction results show that the as-grown NdCOB crystal, is of a single phase and belongs to the monoclinic system with space group Cm. The measurement and calculation of the symmetric second-rank tensors representing thermal properties of the monoclinic crystal, including thermal expansion and conductivity, are described in detail in this paper. The principal coefficients of thermal expansion of the as-grown NdCOB crystal are 6.75189, 6.3727 and 12.13381 (10−6 K−1), respectively, over the temperature range of 303.15–768.15 K. The specific heat of the crystal is 0.65775 J g−1 K−1 at 300.23 K. The principal thermal conductivity parameters are 1.9642, 1.8885 and 2.0374 W m−1 K−1, respectively, at 303.35 K.