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Raman spectroscopy study of the La‐modified (Bi 0.5 Na 0.5 ) 0.92 Ba 0.08 TiO 3 lead‐free ceramic system
Author(s) -
MendezGonzález Y.,
PeláizBarranco A.,
Curcio A.L.,
Rodrigues A.D.,
Guerra J.D.S.
Publication year - 2019
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.5603
Subject(s) - raman spectroscopy , tetragonal crystal system , ferroelectricity , analytical chemistry (journal) , lanthanum , phase (matter) , materials science , crystallography , ion , perovskite (structure) , chemistry , mineralogy , crystal structure , inorganic chemistry , dielectric , physics , optoelectronics , organic chemistry , chromatography , optics
Abstract A Raman spectroscopy study has been performed, at room temperature, on the (Bi 0.5 Na 0.5 ) 0.92 Ba 0.08‐3 x /2 La x TiO 3 lead‐free ceramic system (with x = 0, 1, 2, and 3 at.% La). The signature of the Raman spectra showed that the structural properties were noticeably affected by the La 3+ ‐ions concentration, revealing the coexistence of two phases for the studied compositions. The structural properties showed the presence of both ferroelectric (P4 mm ) and antiferroelectric (P4 bm ) tetragonal phases for the undoped composition ( x = 0). For the La 3+ ‐modified ceramics, both antiferroelectric tetragonal (P4 bm ) and ferroelectric rhombohedral (R3 c ) phases coexist. The behavior of the vibrational modes below 200 cm −1 suggests a predominant substitution of the Na + ion by La 3+ at the dodecahedral site of the perovskite structure. The results revealed a decrease of the tetragonal phase weight percent with the increase of the lanthanum concentration.