Raman spectroscopy study of the La‐modified (Bi0.5Na0.5)0.92Ba0.08TiO3 lead‐free ceramic system. (17th April 2019)

• Record Type: Journal Article
• Authors: Mendez‐González, Y.; Peláiz‐Barranco, A.; Curcio, A.L.; Rodrigues, A.D.; Guerra, J.D.S.
• Is Part Of: Journal of Raman spectroscopy. Volume 50:Number 7(2019)
• Page Start: 1044
• Page End: 1050
• Publication Date: 2019-04-17
• Subjects: BNT–BT -- lead‐free ceramics -- Raman spectra -- structural properties -- vibrational modes; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.5603
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract: A Raman spectroscopy study has been performed, at room temperature, on the (Bi0.5 Na0.5 )0.92 Ba0.08‐3 x /2 La x TiO3 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. Abstract : The Raman scattering study of (Bi0.5 Na0.5 )0.92 Ba0.08‐3 x /2 La x TiO3 lead‐free ceramics revealed structural modifications as a function of the rare‐earth concentration. The confirmation of the phase's coexistence has been also demonstrated.