Improvement of the physical Properties of Bi-Sr Multiferroic Doped with Different Rare Earth Elements

Abstract

Nanomultiferroic materials have increased significantly over the years in view of their projected potential applications in sensors and recording media. BiFeO3 (BFO) is the most interesting magnetoelectric multiferroic compound and has attracted considerable attention because of its ferroelectric and anti-ferromagnetic ordering coexists in a single phase at room temperature. In this work, a series of BiSrFeO3 nanomultiferroic samples were prepared using flash autocombustion technique and the samples were classified into two groups. In first group (BSFO): A series of Bi1-xSrxFeO3; 0 ≤ x ≤ 0.5 were studied the structure, magnetic, and electrical properties. XRD patterns indicated that, all the samples have the same formation of the hexagonal rhombohedral perovskite-like BiFeO3 structure with space group R3c and the particles are in nano size. TEM micrographs indicated the nanostructure nature with a uniform grain growth of nearly hexagonal perovskite shape while change to spherical shape by the Sr substitution at A-site of BFO which improves the particles surface morphology and reduces the average particles size to about 7.5 nm. Infra-red spectrometer (IR) results clarified the 4-absorption peaks (1, 2, 3 and 4) related to BiFeO3. DSC measurements clarified two distinct exothermic transition temperatures at 232.89C and 267.67C. Magnetic susceptibility measurements for samples at different temperatures and field intensities, found that the magnetic properties of the samples enhanced by Sr substitution and confirm the critical concentration at x = 0.4 which also has the highest Néel temperature. The dielectric constant and ac electrical conductivity was studied as a function of frequencies and temperatures and found that as temperature increases; the mobility of hopping electrons also increases thereby increasing the conductivity. In group two (BSREFO): Studying the formation of Bi1-x-ySrxREyFeO3 nanomultiferroic system at x=0.4 and RE = 0.03 where RE are Y3+, Nd3+, Ce3+, and La3+, and their magnetic and electrical properties were carried out.