Lattice assisted dielectric relaxation in four-layer Aurivillius Bi5FeTi3O15ceramic at low temperatures

Deepak Prajapat; Akash Surampalli; Irene Schiesaro; S D Kaushik; Carlo Meneghini; Archna Sagdeo; V G Sathe; V Siruguri; Edmund Welter; V Raghavendra Reddy

doi:10.1088/1361-648X/ac0c3b

Lattice assisted dielectric relaxation in four-layer Aurivillius Bi₅FeTi₃O₁₅ceramic at low temperatures

J Phys Condens Matter. 2021 Jul 8;33(35). doi: 10.1088/1361-648X/ac0c3b.

Authors

Affiliations

¹ UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001, India.
² Dipartimento di Scienze, Universita di Roma Tre, I-00146 Roma, Italy.
³ UGC-DAE Consortium for Scientific Research, Mumbai Centre, R-5 Shed, BARC, Mumbai-400085, India.
⁴ Synchrotrons Utilization Section, RRCAT, Indore, India.
⁵ Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India.
⁶ Deutsches Elektronen-Synchrotron-A Research Centre of the Helmholtz Association, Hamburg 22607, Germany.

PMID: 34139675
DOI: 10.1088/1361-648X/ac0c3b

Abstract

We have investigated magnetic, structural and dielectric properties of Bi₅FeTi₃O₁₅(BFTO) in the temperature range 5K-300 K. Using diffraction, Raman spectroscopy and x-ray absorption fine structure measurements, iso-structural modifications are observed at low temperatures (≈100 K). The analysis of dielectric constant data revealed signatures of dielectric relaxation, concomitant with these structural modifications in BFTO at the same temperatures. Further, employing complementary experimental methods, it is shown that the distribution of Fe/Ti ions in BFTO is random. With the help of techniques that probe magnetism at various length and time scales, it is shown that the phase-pure BFTO is non-magnetic down to the lowest temperatures.

Keywords: EXAFS; Mössbauer spectroscopy; Raman spectroscopy; dielectric relaxation; four layer Aurivillius compound; neutron diffraction.