TY - JOUR
T1 - A Structural Investigation of Hydrous and Anhydrous Rare-Earth Phosphates
AU - Rafiuddin, Mohamed Ruwaid
AU - Grosvenor, Andrew P.
N1 - Publisher Copyright:
© 2016 American Chemical Society.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2016/10/3
Y1 - 2016/10/3
N2 - Rhabdophane- (REPO4·nH2O; RE = La to Dy), monazite- (REPO4; RE = La to Gd), and xenotime-type (REPO4 and RE′PO4·nH2O; RE = Tb to Lu and Y; RE′ = Ho to Lu and Y) rare-earth phosphate materials are being considered for a number of applications including as photonic materials, for biolabeling studies, and as potential nuclear wasteforms. Structural studies of hydrous rare-earth phosphates are rather limited when compared to anhydrous rare-earth phosphates. In this study, rhabdophane- (REPO4·nH2O; RE = La, Nd, Sm, Gd, and Dy) and xenotime-type (REPO4·nH2O; RE = Y and Yb) materials were synthesized by a precipitation-based method and investigated using X-ray diffraction (XRD) and X-ray absorption near-edge spectroscopy (XANES). Examination of the powder XRD data from rhabdophane-type materials has confirmed that the rhabdophane structure crystallizes in the monoclinic crystal system rather than the hexagonal structure that has most often been reported. Materials adopting the rhabdophane- or xenotime-type structure were studied as a function of temperature to understand how the structure varies with increasing annealing temperature. Local structural information was obtained by collecting P K- and RE L1-edge XANES spectra. Examination of P K-edge XANES spectra from rhabdophane- and xenotime-type materials revealed changes in the local environment around P as a function of temperature. These changes were attributed to the removal of water from these structures as a result of high temperature annealing.
AB - Rhabdophane- (REPO4·nH2O; RE = La to Dy), monazite- (REPO4; RE = La to Gd), and xenotime-type (REPO4 and RE′PO4·nH2O; RE = Tb to Lu and Y; RE′ = Ho to Lu and Y) rare-earth phosphate materials are being considered for a number of applications including as photonic materials, for biolabeling studies, and as potential nuclear wasteforms. Structural studies of hydrous rare-earth phosphates are rather limited when compared to anhydrous rare-earth phosphates. In this study, rhabdophane- (REPO4·nH2O; RE = La, Nd, Sm, Gd, and Dy) and xenotime-type (REPO4·nH2O; RE = Y and Yb) materials were synthesized by a precipitation-based method and investigated using X-ray diffraction (XRD) and X-ray absorption near-edge spectroscopy (XANES). Examination of the powder XRD data from rhabdophane-type materials has confirmed that the rhabdophane structure crystallizes in the monoclinic crystal system rather than the hexagonal structure that has most often been reported. Materials adopting the rhabdophane- or xenotime-type structure were studied as a function of temperature to understand how the structure varies with increasing annealing temperature. Local structural information was obtained by collecting P K- and RE L1-edge XANES spectra. Examination of P K-edge XANES spectra from rhabdophane- and xenotime-type materials revealed changes in the local environment around P as a function of temperature. These changes were attributed to the removal of water from these structures as a result of high temperature annealing.
KW - hydrous rare-earth phosphates
KW - Anhydrous rare-earth phosphates
UR - http://www.scopus.com/inward/record.url?scp=84990050969&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.6b01471
DO - 10.1021/acs.inorgchem.6b01471
M3 - Article
AN - SCOPUS:84990050969
VL - 55
SP - 9685
EP - 9695
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 19
ER -