Journal Article

Probing the structural, optical absorption, dielectric and impedance properties of Sr-modified BaMnO3 ceramics

Jena, Satyajeet, Mishra, Dilip Kumar, Nayak, Itishree, Behera, Debadhyan

2025

Overview

This work probes the structural, optical and temperature-dependent dielectric properties of BaMnO 3 and Ba 0.9 Sr 0.1 MnO 3 multiferroic ceramics prepared by conventional solid state reaction technique. XRD analysis indicates rhombohedral perovskite structure of BaMnO 3 . When 10 wt.% Sr is added in the BaMnO 3 matrix against Ba, the rhombohedral structure transforms into hexagonal perovskite structure. The average crystallite size of BaMnO 3 and Ba 0.9 Sr 0.1 MnO 3 were found to be ~ 92 nm and ~ 63 nm, respectively. The lattice parameter and the unit cell volume also decrease with the addition of Sr in pure BaMnO 3 . Through EDX analysis, the presence of all the constituents in the final samples are verified. The optical band gap of BaMnO 3 decreases from 2.33 eV to 1.75 eV, primarily attributed to SrMnO 3 phase and grain boundary effects. A much higher value of dielectric constant i.e. ~ 19,800 at 200 °C with respect to 10 Hz frequency has been achieved with 10 wt.% strontium doping in BaMnO 3 , which may boost the efficiency of electronic devices made up of dielectric materials. The impedance analysis confirms the negative temperature coefficient of resistance (NTCR) behaviour of the sample and semicircular arc Nyquist plot supports the semiconducting nature with non-Debye type of relaxation mechanism in both the samples.

• Publisher: Springer US,Springer Nature B.V
• Subject: Ceramics / Characterization and Evaluation of Materials / Chemistry and Materials Science / Crystallites / Dielectric properties / Dielectrics / Grain boundaries / Impedance / Materials Science / Nyquist plots / Optical and Electronic Materials / Optical properties / Perovskite structure / Perovskites / Strontium / Temperature dependence / Unit cell