The carbonate location in mixed calcium and strontium carbonated apatites. (15th March 2020)

• Record Type: Journal Article
• Authors: Yoder, Claude H.; Lyu, Xueying
• Is Part Of: Polyhedron. Volume 179(2020)
• Publication Date: 2020-03-15
• Subjects: Mixed cation apatite -- Carbonated apatite -- Strontium apatite -- IR of carbonated apatite -- A-type carbonated apatite -- Channel environment model; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2020.114365
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: This study of the location of the carbonate in mixed Ca/Sr apatites shows that an increase in the strontium content of the apatite channel produces an expansion of the channel volume, which leads to an increased stability of carbonate in the channel. The cogwheel- like control of channel carbonate can be utilized to prepare apatites appropriate for various applications. Abstract: Mixed calcium/strontium carbonated apatites were obtained by aqueous addition of mixtures of calcium and strontium nitrate to NH4 H2 PO4 and Na2 CO3 in the presence of both low and high sodium concentrations. The calcium: strontium ratios in the products were obtained by xrf and carbonate percentages by combustion analysis. Peak-fitting of the asymmetric carbonate region of the IR spectra, using the procedures developed previously, showed that an increase in the percentage of strontium in the apatite led to an enhancement in the percentage of A-type carbonate. Because of the larger size of Sr 2+ relative to Ca 2+, this result can be attributed to an expansion of the channel, which leads to an increased stability of carbonate in the channel. The cogwheel- like control of channel carbonate can be utilized to prepare apatites appropriate for various applications.