Effects of frequency, temperature, and dc bias electric field on the dielectric properties of methylammonium lead iodide from the perspective of a relaxor-like ferroelectric

Autor(es)

Minussi, F. B. ^[1] ; Reis, S. P. ^{[2, 1]} ; Araujo, E. B. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, Dept Phys & Chem, BR-15385000 Ilha Solteira - Brazil

^[2] Fed Inst Educ Sci & Technol Sao Paulo, BR-15503110 Votuporanga - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACTA MATERIALIA; v. 219, OCT 15 2021.
• Citações Web of Science: 0

Resumo

This work reports dielectric properties of methylammonium lead iodide as a function of frequency, temperature, and dc bias electric field studied in terms of grain and grain boundary contributions. These results were analyzed from the perspective of a relaxor-like ferroelectric nature. The temperature dependence of dielectric permittivity at different frequencies showed a wide dispersion in the vicinity of the tetragonal-cubic phase transition, suggesting a relaxor ferroelectric feature after excluding artifacts as Maxwell-Wagner effects and dc contributions. The results from plots of the Vogel-Fulcher and the modified Curie-Weiss laws indicate the existence of a freezing temperature of the dipoles responsible for the relaxor character of the material (T-f similar to 270 K) and a diffuse phase transition at high temperatures (gamma similar to 1.52-1.74). Measurements on heating and cooling protocols under a dc bias electric field suggest field-induced polarized domains like relaxor ferroelectric. The observed signatures of transitions between non-ergodic and ergodic relaxors to ferroelectric states were attributed to polar nano regions dynamics, suggesting a critical electric field around 0.03 kV cm(-1). (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 17/13769-1 - Materiais multiferróicos e ferroelétricos para conversores de energia: síntese, propriedades, fenomenologia e aplicações
• Beneficiário: José Antonio Eiras
• Modalidade de apoio: Auxílio à Pesquisa - Temático