title: The crystal chemistry of the alkaline-earth apatites A(10)(PO(4))(6)Cu(x)O(y)(H)(z) (A = Ca, Sr and Ba).
abstract: The crystal chemistry of the cuprate apatites A(I)(4)A(II)(6)(PO(4))(6)Cu(x)O(y)(H)(z) (A = Ca, Sr and Ba) was investigated by powder X-ray (PXRD) and neutron diffraction (PND) and X-ray photoelectron spectroscopy (XPS). The refined crystal structures confirmed earlier X-ray diffraction studies that showed copper resides in the apatite channels and additionally, located hydrogen. For all materials copper is primarily divalent (Cu(2+)) but in the calcium and strontium analogues co-exists with minor Cu(3+). This is in contrast with a previous work where Cu(1+) and Cu(2+) were reported.
authors.affiliation: School of Materials Science & Engineering, Nanyang Technological University, Singapore. tbaikie@ntu.edu.sg
authors.forename: Tom
authors.initials: T
authors.lastname: Baikie
authors.forename: George M H
authors.initials: GM
authors.lastname: Ng
authors.forename: S
authors.initials: S
authors.lastname: Madhavi
authors.forename: Stevin S
authors.initials: SS
authors.lastname: Pramana
authors.forename: Kevin
authors.initials: K
authors.lastname: Blake
authors.forename: Margaret
authors.initials: M
authors.lastname: Elcombe
authors.forename: T J
authors.initials: TJ
authors.lastname: White
mesh_terms: D001031:Apatites / Q000737:chemistry*; D001464:Barium / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D008673:Metals, Alkaline Earth / Q000737:chemistry*; D008968:Molecular Conformation; D013324:Strontium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D008673:Metals, Alkaline Earth; D001464:Barium; D003300:Copper; D002118:Calcium; D013324:Strontium