Revealing of Core Shell Effect on Frequency-Dependent Properties of Bi-based Relaxor/Ferroelectric Ceramic Composites

Mohsin Saleem; Lim Dong Hwan; In-Sung Kim; Min-Soo Kim; Adnan Maqbool; Umair Nisar; Syed Atif Pervez; Umer Farooq; Muhammad Umer Farooq; Hafiz Muhammad Waseem Khalil; Soon-Jong Jeong

doi:10.1038/s41598-018-32133-7

Revealing of Core Shell Effect on Frequency-Dependent Properties of Bi-based Relaxor/Ferroelectric Ceramic Composites

Sci Rep. 2018 Sep 20;8(1):14146. doi: 10.1038/s41598-018-32133-7.

Authors

Mohsin Saleem^{1

2}, Lim Dong Hwan³, In-Sung Kim³, Min-Soo Kim³, Adnan Maqbool⁴, Umair Nisar⁵, Syed Atif Pervez⁶, Umer Farooq⁶, Muhammad Umer Farooq⁷, Hafiz Muhammad Waseem Khalil^{7

8}, Soon-Jong Jeong⁹

Affiliations

¹ Battery Research Center, Korea Electro-technology Research Institute (KERI), Changwon, 641-120, Republic of Korea. saleem.mohsin@yahoo.com.
² School of Chemical and Material Engineering, National University of Science and Technology, Islamabad, Pakistan. saleem.mohsin@yahoo.com.
³ Battery Research Center, Korea Electro-technology Research Institute (KERI), Changwon, 641-120, Republic of Korea.
⁴ Department of Metallurgical & Materials Engineering, University of Engineering and Technology, Lahore, Pakistan.
⁵ Center of Advanced Materials (CAM), Qatar University, Doha, Qatar.
⁶ Department of chemical and petroleum engineering, university of Calgary, Alberta, Canada.
⁷ Department of mechanical engineering, Khwaja Fareed university of engineering and information technology, Rahim yar khan, Punjab, Pakistan.
⁸ Department of Electrical Engineering, UCET, University of Sargodha, Sargodha, Pakistan.
⁹ Battery Research Center, Korea Electro-technology Research Institute (KERI), Changwon, 641-120, Republic of Korea. sjjeong@keri.re.kr.

Abstract

In this study, electromechanical characteristics of (1-x) Bi_0.5Na_0.5TiO₃-xSrTiO₃ (ST26, x = 0.26)/(1-y) Bi_0.5Na_0.5TiO₃-ySrTiO₃ (ST10, y = 0.1) (matrix/seed) composites were studied. The ST26 (high relaxor phase) and ST10 (a relaxor ferroelectric (RF), high ferroelectric phase) composite with large (r-ST26-ST10) and small (t-ST26-ST10) grains exhibited frequency-related dielectric properties and large strain response at a low triggering electric field (an incipient piezoelectricity). It is ascribed to a matrix-seed effect originating from the inhomogeneous composition due to the presence of two phases. The r-ST26-ST10 composite sintered at 4 h, prominent material, showed a high normalized dynamic strain (d₃₃*) of ~700 pm/V (large grains) with stable frequency dependence properties at a low field of 40 kV/cm. The properties of the r-ST26-ST10 composite exhibit less decay with frequency-related polarization and strain compared to those of t-ST26-ST10 composite. The increase in soaking time promotes the diffusion and homogenization of the microstructure in composites, leading to changes in the core-shell structure in the solid solution. The polarization and strain of the ST26-ST10 composites with the frequency are linked to the stability of the internal random fields created by non-ergodic relaxor phase of seed and the amount of phase change in the ergodic relaxor matrix.