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Abnormal Raman spectra in Er‐doped BaTiO 3 ceramics
Author(s) -
Lu DaYong,
Cheng Wei,
Sun XiuYun,
Liu QiaoLi,
Li DeXu,
Li ZhongYu
Publication year - 2014
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.4575
Subject(s) - raman spectroscopy , tetragonal crystal system , ion , analytical chemistry (journal) , doping , electron paramagnetic resonance , vacancy defect , dopant , chemistry , materials science , crystallography , crystal structure , nuclear magnetic resonance , optics , physics , optoelectronics , organic chemistry , chromatography
Greatly enhanced and abnormal Raman spectra were discovered in the nominal (Ba 1 − x Er x )Ti 1 − x /4 O 3 ( x = 0.01) (BET) ceramic for the first time and investigated in relation to the site occupations of Er 3+ ions. BaTiO 3 doped with Ti‐site Er 3+ mainly exhibited the common Raman phonon modes of the tetragonal BaTiO 3 . Er 3+ ions substituted for Ba sites are responsible for the abnormal Raman spectra, but the formation of Er Ba • − Er Ti ' defect complexes will decrease spectral intensity. A large increase in intensity showed a hundredfold selectivity for Ba‐site Er 3+ ions over Ti‐site Er 3+ ions. A strong EPR signal at g = 1.974 associated with ionized Ba vacancy defects appeared in BET, and the defect chemistry study indicated that the real formula of BET is expressed by (Ba 1 − x Er 3 x /4 )(Ti 1 − x /4 Er x /4 )O 3 . These abnormal Raman signals were verified to originate from a fluorescent effect corresponding to 4 S 3/2 → 4 I 15/2 transition of Ba‐site Er 3+ ions. The fluorescent signals were so intense that they overwhelmed the traditional Raman spectra of BaTiO 3 . The significance is that the abnormal Raman spectra may act as a probe for the Ba‐site Er 3+ occupation in BaTiO 3 co‐doped with Er 3+ and other dopants. A new broad EPR signal at g = 2.23 was discovered, which originated from Er 3+ Kramers ions. Copyright © 2014 John Wiley & Sons, Ltd.