Synthesis of Cobalt-Doped Bi 12 NiO 19 : Structural, Morphological, Dielectric and Magnetic Properties
- PDF / 1,861,907 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 71 Downloads / 210 Views
RESEARCH ARTICLE-PHYSICS
Synthesis of Cobalt-Doped Bi12 NiO19 : Structural, Morphological, Dielectric and Magnetic Properties M. Rajamoorthy1 · D. Geetha1
· A. Sathiya Priya2
Received: 27 January 2020 / Accepted: 18 August 2020 © King Fahd University of Petroleum & Minerals 2020
Abstract The influence of cobalt doping on bismuth nickelate (Bi12 NiO19 ) synthesized by sol–gel method has been investigated. The X-ray powder diffraction analysis proves that bismuth nickelate possesses cubic perovskite structure, and the same is retained even after Co doping. The average crystallite sizes were found to be in the range of 42–60 nm as estimated by Scherrer’s formula. The morphology of the samples analyzed by scanning electron microscopy reveals irregular-shaped structures of the samples. However, incorporation of Co has led to a significant morphological transformation. The dielectric properties were found to be consistent with the Koop’s phenomenological theory. Nyquist plots exhibit only one incomplete and distorted semicircle for all the samples specifying that the relaxation process deviates from the ideal Debye-type behavior. Magnetization measurements carried out using vibrating sample magnetometry (VSM) revealed paramagnetic behavior of the investigated samples. The results obtained from the impedance analysis give a true picture of the electrical behavior of the sample. The cobalt-doped bismuth nickelate ceramics have good prospects in scientific and industrial applications in the fields of sensors and memory devices. Keywords Sol–gel · Bismuth nickelate · Dielectric · Cole–Cole plots · Magnetic
1 Introduction Nanostructured materials with perovskite structure have been extensively studied in the last few years due to their potential for a variety of applications. Perovskites of bismuthcontaining metallic oxides play indispensable role in microelectronics owing to their incredible multiferroic behavior leading to newer device applications [1]. Their fascinating magnetic, dielectric and transport characteristics are a consequence of the coupling of spin, charge and orbital degrees of freedom [2]. Bismuth nickelate is a single-phase multiferroic, whose co-existing magnetoelectric character coupled with ferroelasticity deserves potential applications in microwave devices, sensors, transducers and read/write devices [3, 4]. This is a lead-free and environmental friendly material.
B
D. Geetha [email protected]
1
Department of Physics, Government Arts College, Ariyalur 621713, India
2
Functional Materials Lab, Department of Physics, Madras Institute of Technology, Anna University, Chennai 600044, India
The exciting applications of Bi12 NiO19 (BNO) include the emerging fields of spintronics, nonvolatile multiple-state memories and lead-free ferroelectric materials [5]. BNO has a perovskite structure, where Bi3+ ions are located at Asite and Ni3+ ions at B-site. Ferroelectric polarization is a consequence of the distorted crystal structure while the transition-metal ions located at the B-sites make it ferrom
Data Loading...
