TY - JOUR
T1 - The location of Mn (MnO
T2 - 2.0 wt%) in fluorapatite from Lavra da Golconda, near Governador Valadares, Minas Gerais, Brazil
AU - Arima, Hiroshi
AU - Kida, Yusuke
AU - Mikouchi, Takashi
AU - Sugiyama, Kazumasa
N1 - Funding Information:
EXAFS and XANES measurements were carried out at BL7C and BL15A1 beamlines at the Photon Factory, with the approval of the Photon Factory Program Advisory Committee (Proposal No. 2015G575 and 2016G130). This work was supported by JSPS KAKENHI Grant Number JP15K13589.
Publisher Copyright:
© 2018 Japan Association of Mineralogical Sciences.
PY - 2018
Y1 - 2018
N2 - The local structural features around Mn in a transparent pale blue Mn-bearing fluorapatite (MnO: 2.0 wt%) from Lavra da Golconda, Brazil were investigated by a combined analysis of single crystal X-ray diffraction and XAFS. The crystal structure with the optimized formula (Ca4.83Mn0.15 2+Sr0.02)P3O12F with space group P63/m, a = 9.384(2), c = 6.8842 (6) Å, Z = 2 has been refined to R = 1.92% for the unique 555 reflections (Mo Kα). The structural refinement suggests that Mn almost exclusively occupies the Ca1 site. The EXAFS analysis indicates that Mn at the Ca1 site is surrounded by nine oxygen atoms with six shorter bonds and three longer bonds. BVS calculated for the local environment around Mn shows good agreement with the expected valence state of Mn. The present EXAFS results suggest that the longer bond distances (Ca1-O3) in fluorapatite structures will not be affected by Mn due to weak bonding interactions.
AB - The local structural features around Mn in a transparent pale blue Mn-bearing fluorapatite (MnO: 2.0 wt%) from Lavra da Golconda, Brazil were investigated by a combined analysis of single crystal X-ray diffraction and XAFS. The crystal structure with the optimized formula (Ca4.83Mn0.15 2+Sr0.02)P3O12F with space group P63/m, a = 9.384(2), c = 6.8842 (6) Å, Z = 2 has been refined to R = 1.92% for the unique 555 reflections (Mo Kα). The structural refinement suggests that Mn almost exclusively occupies the Ca1 site. The EXAFS analysis indicates that Mn at the Ca1 site is surrounded by nine oxygen atoms with six shorter bonds and three longer bonds. BVS calculated for the local environment around Mn shows good agreement with the expected valence state of Mn. The present EXAFS results suggest that the longer bond distances (Ca1-O3) in fluorapatite structures will not be affected by Mn due to weak bonding interactions.
KW - Mn-bearing fluorapatite
KW - Single crystal X-ray diffraction
KW - XAFS
UR - http://www.scopus.com/inward/record.url?scp=85049538826&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85049538826&partnerID=8YFLogxK
U2 - 10.2465/jmps.170928
DO - 10.2465/jmps.170928
M3 - Article
AN - SCOPUS:85049538826
VL - 113
SP - 119
EP - 125
JO - Journal of Mineralogical and Petrological Sciences
JF - Journal of Mineralogical and Petrological Sciences
SN - 1345-6296
IS - 3
ER -