The crystal structure of single crystalline PrCa${}_4$O[BO${}_3$]${}_3$

PrCa${}_4$O[BO${}_3$]${}_3$ was grown as a single crystal by the Czochralski method. The precursor material was synthesized by solid state reaction under O${}_2$ atmosphere and sintered after grinding under N${}_2$ atmosphere with a content of 20% H${}_2$. The Czochralski crystal growth proceeded under N${}_2$ atmosphere with an <010> oriented GdCa${}_4$O[BO${}_3$]${}_3$ crystal seed. A PrCa${}_4$O[BO${}_3$]${}_3$ crystal with a cylinder length of 20 mm, a diameter of 15 mm, and weight of 23.1 g was obtained. The crystal structure was solved from single crystal X-ray diffraction data in the monoclinic crystal system with space group C1m1 (No. 8), the lattice parameters a = 8.1293(6) Å, b = 16.062(1) Å, c = 3.6023(2) Å, β = 101.371(2)°, formula units of 2 and final R- and wR2-values below 3.8%. A mixed occupancy between Pr and Ca of 6.0% was found.