Impedance Study of Temperature-Stable Relaxor Dielectrics in the System of BCT-BMT Ceramics

Aurang Zeb; Amir Ullah; Amir Sohail Khan; Fazli Akram; Muhammad Habib; Vineet Tirth; Ali Algahtani; S J Milne; Amnah Mohammed Alsuhaibani; Moamen S Refat; Abid Zaman

doi:10.1021/acsomega.3c01979

Impedance Study of Temperature-Stable Relaxor Dielectrics in the System of BCT-BMT Ceramics

ACS Omega. 2023 Jun 15;8(25):22955-22963. doi: 10.1021/acsomega.3c01979. eCollection 2023 Jun 27.

Authors

Aurang Zeb¹, Amir Ullah¹, Amir Sohail Khan¹, Fazli Akram², Muhammad Habib³, Vineet Tirth^{4

5}, Ali Algahtani^{4

5}, S J Milne⁶, Amnah Mohammed Alsuhaibani⁷, Moamen S Refat⁸, Abid Zaman⁹

Affiliations

¹ Department of Physics, Islamia College Peshawar, Peshawar 25120, KP, Pakistan.
² Department of Chemistry, Clark Atlanta University, Atlanta, Georgia 30314, United States.
³ State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China.
⁴ Mechanical Engineering Department, College of Engineering, King Khalid University, Abha 61421, Asir, Kingdom of Saudi Arabia.
⁵ Research Center for Advanced Materials Science (RCAMS), King Khalid University, Guraiger, P.O. Box 9004, Abha 61413, Asir, Kingdom of Saudi Arabia.
⁶ School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
⁷ Department of Physical Sport Science, College of Education, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
⁸ Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
⁹ Department of Physics, Riphah International University, Islamabad 44000, Pakistan.

Abstract

Preparation of a lead-free system (Ba_0.8Ca_0.2)TiO_3-xBi(Mg_0.5Ti_0.5)O₃ (BCT-BMT) with x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5 was carried out using a solid-state reaction technique. X-ray (XRD) diffraction analysis confirmed a tetragonal structure for x = 0, which shifted to cubic (pseudocubic) at x ≥ 0.1. From Rietveld refinement, a single phase with a tetragonal symmetry model (P4mm) was observed for x = 0, and however, for sample x = 0.1 and sample x = 0.5, the data are modeled to cubic (Pm3m). Composition x = 0 showed a prominent Curie peak, typical of ordinary ferroelectrics with a Curie temperature (T_c) ∼130 °C, modified to a typical relaxor dielectric at x ≥ 0.1. However, samples at x = 0.2-0.5 displayed a single semicircle attributed to the bulk response of the material, whereas a slightly depressed second arc appeared for x = 0.5 at 600 °C, indicating a slight contribution to the electrical properties, ascribed to the grain boundary of the material. Finally, the dc resistivity increased with the increase of the BMT content and the solid solution increased the activation energy from 0.58 eV at x = 0 to 0.99 eV for x = 0.5. Adding the BMT content eliminated the ferroelectric behavior at compositions x ≥ 0.1 and led to a linear dielectric response and electrostrictive behavior with a maximum strain of 0.12% for x = 0.2.