STUDIES OF STRUCTURAL DIELECTRIC AND IMPEDANCE PROPERTIES OF RARE EARTH DOPED MULTIFERROIC COMPOSITES BiFeO3 NaNbO3

Abstract

Recently, the development and extensive research in material science and condensed material Physics has largely affected and transformed our society thereby increasing the need to understand the underlying mechanism involved in developing multiferroic (MF) ordering and magneto electric coupling in composite materials. The existence of MF in single phase can have a strong spin charge coupling but the existence of polarization, magnetization and magnetic and ferroelectric transition temperature are often very small which affects its use in device application. However, it is observed for many MF composite [1, 2] that there exists a strong magneto-electric (ME) coupling at room temperature (RT), which makes them a suitable material for fabricating devices and industrial application. This ME coupling is relevant for designing new multifunctional devices [3, 4] for potential applications. However, most of the multiferroic materials possess weak ME coupling which limits their practical applications. MFs are the class of material in which the application of magnetic field causes the changes in electrical properties and vice versa. The ME effect is an indirect process i.e., when a magnetic field is applied to materials it causes the strain due to magnetostriction and lattice strain is responsible for electrical properties due to piezoelectric response. So for having strong ME coupling, the composites with combination of different kinds of materials with both magnetostriction and piezoelectric properties are essential newline