Preparation, structural, spectroscopic and magneto-electric properties of multiferroic cadmium doped neodymium manganite

Abstract

Cadmium doped neodymium manganite having general formula Nd1−xCdxMnO3 where x = 0.05, 0.20 were prepared by solid state reaction technique. The effect of cadmium doping on the structural, dielectric and magnetic properties were understood by various characterization probes like X-ray diffractometer, scanning electron microscope, energy dispersive X-ray analyzer, Fourier transform infrared spectroscope, impedance analyzer, vibrating sample magnetometer and resistivity measurements for low temperature using four probe method. XRD analysis confirms the single phase formation with perovskite structure having orthorhombic phase. The crystallite size was found to be in the range of 30–50 nm as determined by Debye-Scherer relation and Williamson’s Hall method. Density of the samples were determined theoretically and experimentally and compared with the results obtained by Archimedes principle. The scanning electron micrograph shows that the particle size distribution is almost homogeneous and spherical in shape for all grains. FTIR spectra depict the presence of various atomic bonds within a molecule and the present study depicts the presence of the Mn–O bond and O–Mn–O stretching for these compositions. A very large value of dielectric constant was observed at low frequencies due to the presence of grains and interfaces. The variation of dielectric constant value with the change in frequency and temperature were studied and compared for two compositions. Magnetization study confirms the phase transition of the materials from the paramagnetic to ferromagnetic behaviour of the material at low temperature. The variation in resistance below room temperature were studied and compared for both the compositions.