High temperature extended x-ray absorption fine structure study of multiferroic BiFeO3.
Local atomic structure modifications around Fe atoms in polycrystalline multiferroic BiFeO(3) are studied by Fe K edge x-ray absorption spectroscopy as a function of temperature across the Néel temperature (T(N) = 643 K) in order to reveal local structure modifications related to the magnetic transition. This work demonstrates that on crossing T(N) the local structure around Fe shows peculiar changes: the Fe-O bond lengths get shorter, the ligand symmetry increases and the Fe-O bond length disorder (σ(2)) deviates from Debye behaviour. These results suggest that the structural transition at the ferroelectric Curie temperature (T(C) = 1103 K) is anticipated by early local rearrangement of the structure starting already at T(N).
UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore-452001, India. vrreddy@csr.res.in
V
V
Raghavendra Reddy
Carlo
C
Meneghini
Deepti
D
Kothari
Ajay
A
Gupta
Giuliana
G
Aquilanti