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Title: Photoluminescence detection of symmetry transformations in low-dimensional ferroelectric ABO 3 perovskites
Symmetry-dependent properties such as ferroelectricity are suppressed at room temperature in Pb-free ABO 3 perovskites due to antiferrodistortive dynamics (octahedral rotations/tilts), resulting in the preferential stabilization of centrosymmetric crystals. For this reason, defect engineering (Ca doping, oxygen vacancy, etc. ) has been leveraged to break the symmetry of these crystals by inducing symmetry/structural transitions to modify the local A/B-site environment. This work demonstrates the use of in situ / ex situ photoluminescence spectroscopy to systematically detect symmetry/structural transformations in prototypical ferroelectric ABO 3 perovskites. These baseline optical responses are compared to recently synthesized Ca x Sr 1−x NbO 3 (CSNO) nanocrystals, which undergoes similar ferroelectric/structural phase transitions. Furthermore, the resultant PL response is corroborated with X-ray diffraction (XRD) and absorption spectroscopy (XAS) measurements to confirm the structural changes. This ability to directly monitor the local site symmetry within ABO 3 perovskites via photoluminescence spectroscopy can be used to screen for temperature- and defect-induced ferroelectric transitions.  more » « less
Award ID(s):
1709902
PAR ID:
10199683
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Journal of Materials Chemistry C
Volume:
8
Issue:
31
ISSN:
2050-7526
Page Range / eLocation ID:
10767 to 10773
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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