This work investigates atomic-scale partial B-site ordering in the complex perovskite relaxor lead iron tungstate, PbFe1−xWx0.5Fe1/3+xW2/3−x0.5O3 (0 < x < 1/3), abbreviated as PFWO, using Time Differential Perturbed Angular Correlation (TDPAC) spectroscopy. The radioactive isotope 111mCd (decaying to 111Cd) is employed as a sensitive tracer probe to explore the local electric and magnetic environments at atomic sites within the lattice. Temperature-dependent TDPAC measurements performed over a broad range (9–420 K) reveal the persistence of local electric field gradients at the Pb2+ sublattice in the face-centered cubic (Fm-3 m) structure. This observation indicates local symmetry breaking due to partial B-site ordering, wherein Fe3+ and W6+ ions exhibit a degree of site preference, and confirms the presence of short-range polar ordering characteristic of relaxor ferroelectric behavior. Moreover, the detection of a non-zero local magnetic field at the Pb site—where complete spin compensation would be expected in an ideal antiferromagnetic configuration—provides compelling evidence for ferrimagnetic ordering. This ferrimagnetism is attributed to partial B-site cation ordering, resulting in unequal sublattice magnetizations and incomplete spin cancellation. These findings highlight the critical role of atomic-scale B-site ordering in mediating the coexistence of relaxor ferroelectricity and ferrimagnetism in PFWO.
Dang et al. (Thu,) studied this question.