Discussion On The Structure Of Boron Containing Apatite

摘要

The single crystals of boron containing apatite (BAP) with the formula Ca_(9.93)B_(0.83)P_(5.84)O_(25.79) has been grown using flux method and characterised before. On the other hand a structure resembling BAP has been observed during the synthesis and investigation of the melting behaviour of Ca_3BPO_7 in our work. Upon heating at 1440 ℃ and cooling, colorless crystals were obtained. The structure was found to be trigonal with the space group P3~- and z = 1. The unit cell parameters are a = 9.275 (6), c = 6.952 (2) A° which are in close aggreement with the reported Sr Na BAP compound. Ca BAP was also obtained in the powder form using three different solid state reactions and the x- ray powder diffraction pattern was indexed with the unit cell parameters of a = 9.455 (6) and c = 6.905 ( 2 ) which were the same as the literature data of Ca BAP of trigonal structure with the space group P3~- and z = 1. The IR data agreed with reported values.