In situ Raman and electric modulus study of NBT-ST-KNN ceramics: An insight into temperature evolution of relaxor dynamics
Year: 2025
Type: article
Abstract: Polar nanoregions (PNRs) are often argued to be the key factor in enhancing the functional properties of relaxor-based ferroelectrics. The creation and relaxation of these polar entities are believed to be strongly temperature-dependent, but the explanation is still unclear. In this investigation we have chosen a well-established relaxor system (0.8- x )(Na 0.5 Bi 0.5 )TiO 3 -0.2SrTiO 3 - x (K 0.5 Na 0.5 )NbO 3 ; ( x = 0.005, 0.01, 0.04 and 0.1) to probe into the thermal dynamics of PNRs using in-situ Raman and electric modulus formalism. The Raman spectra segregate into different temperature zones corresponding to ferroelectric-relaxor transition (T F-R ), maximum dielectric constant (T m ) and Burn’s temperature (T B ). A closer introspection of width and position of peak peaks around these temperatures depicts the existence of local structural heterogeneities. Further, the frequency-dependent electric modulus, M"(f) study demarcates high-frequency shoulder (related to PNR relaxation) from intermediate frequency peak corresponding to bulk response. Analysis of Z"(f) and M"(f) predict temperature evolution of long-range ordered regions to localized relaxations.
Source: Materials Research Bulletin
Authors: Arpita Singha, Swetapadma Praharaj, Dibyaranjan Rout
Institutions: Indian Institute of Technology Hyderabad, KIIT University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,610
OpenAlex ID: W4409970951