Infrared studies of apatites. II. Preparation of normal and isotopically substituted calcium, strontium, and barium hydroxyapatites and spectra-structure-composition correlations

摘要: Procedures are described for preparation of calcium, strontium, and barium hydroxyapatites, their deuterated analogs, calcium hydroxyapatite enriched with isotopic particular emphasis on purity, stoichiometry, crystal perfection, gravimetrically monitoring the apatite composition. The effects low temperature differences in physical properties apatites infrared vibrational frequencies discussed. Shifts internal phosphate modes to higher frequencies, barium-strontium--calcium sequence also cooling, attributed primarily increased interphosphate repulsion concomitant lattice contraction. Causes variation intensities OH considered from several viewpoints including presence weak OH-O bonding which is neither conclusively established nor rejected. Finally, marked increases band barium--strontium--calcium rather than other effects.