TY  - JOUR
AU  - Sohn, Yoo Jung
AU  - Baran, V.
AU  - Gilles, R.
AU  - Roth, G.
AU  - Vassen, Robert
TI  - Combined X-ray and Neutron Powder Diffraction Study on B-site Cation Ordering in Complex Perovskite La2(Al1/2MgTa1/2)O6
JO  - Solids
VL  - 4
IS  - 1
SN  - 2673-6497
CY  - Basel
PB  - MDPI
M1  - FZJ-2023-01374
SP  - 87-93
PY  - 2023
AB  - Complex perovskite La2(Al1/2MgTa1/2)O6 (LAMT) crystallizes in a monoclinic unit cell with space group P21/n at room temperature. Its B-site cations are ordered in a rock-salt-type arrangement. Previously, the full occupancy of Mg on the 2c-Wyckoff position was deduced from powder X-ray diffraction (PXRD). However, conventional X-rays could not properly resolve the mixed occupation on the B-site, since there is little scattering contrast between the neighbouring elements Mg and Al of the periodic table. Hence, complementary neutron diffraction studies were carried out to verify the exact B-site cation ordering in the unit cell. In this specific configuration of the B-cations, with its occupancy ratio and the presence of a heavy element Ta as well as neighbouring elements Mg and Al, only the strategy of a combined Rietveld analysis using both the X-ray and neutron diffraction data simultaneously succeeded in elucidating an accurate B-site cation ordering in this complex perovskite system. A full occupancy of Mg on the 2c-Wyckoff position and each a half occupancy of Al and Ta on the 2d-Wyckoff position could be resolved for the rock-salt-type ordering of the B-site cations in the monoclinic unit cell of LAMT.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001114876600001
DO  - DOI:10.3390/solids4010006
UR  - https://juser.fz-juelich.de/record/1005226
ER  -