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
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 temperatu...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | Brasil |
| Recursos: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/222259 |
| Acesso em linha: | http://dx.doi.org/10.1016/j.actamat.2021.117235 http://hdl.handle.net/11449/222259 |
| Access Level: | acceso abierto |
| Palavra-chave: | Dielectric properties Ferroelectricity Halide perovskite Relaxor |
| 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 (Tf ∼ 270 K) and a diffuse phase transition at high temperatures (γ ∼ 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. |
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