Crystal Structures, Optical, Electrical and Magnetic Properties of Ca 0.9 Sr 0.1 Mn 1− x Mo x O 3 Perovskites for the Applications of Multifunctional Devices

Abstract

The standard solid-state reaction method was employed to synthesize the polycrystalline Ca0.9Sr0.1Mn1−xMoxO3 (CSMMO with x = 0.00, 0.02, 0.04, 0.06, and 0.08) ceramics and each composition was sintered at 1300˚C for 4 hours. The crystal structure, microstructure, optical properties, electrical properties, complex initial permeability, and DC magnetization of the prepared compo-sitions were carried out. The compound exhibited perovskite structure with the transformation of phase from orthorhombic symmetry for x = 0.00 to x = 0.04 samples into a tetragonal symmetry for the samples x = 0.06 and x = 0.08. The lattice constant was found to be enhanced with the doping of Mo concen-tration. The mean grain size was estimated in the micrometer, with values from 1.3045 to 3.0124 µm. Energy band gap (Eg) was determined for each composition and the magnitudes of Eg were lying between 1.85 - 4.00 eV. The Eg values firstly decreased with the doping content up to 2% and, then, in-creased for 4% to 6% Mo contents, where it again very slightly decreased for 8% Mo content. The lowest value of Eg was obtained for the x = 0.02 composi-tion. The FTIR spectra revealed the existence of a metal oxide band in each of the prepared samples and supported the formation of a single-phase com-pound of synthesized material without any impurity, as confirmed by the XRD analysis. The electrical properties, such as resistivity and AC conductiv-ity, were collected using the Impedance analyzer at room temperature. The resistivity and AC conductivity increased with the addition of dopant con-centration. The frequency-dependent conductivity spectra showed three dis-tinct regions. The complex initial permeability ( ) was found to be en-hanced with the addition of Mo and the highest value was noticed the 6% Mo dopant sample. On the other hand, the lowest loss factor was obtained for the samples x ≥ 0.06. The M-H hysteresis loops of various Ca0.9Sr0.1Mn1−xMoxO3 ceramics were measured both at room temperature (300 K) and low temper-ature (5 K). The values of saturation magnetization (Ms) and retentivity (Mr) were found to be larger at low temperatures than at room temperature (RT), although no saturation was obtained for any compositions. The highest satu-ration magnetization obtained at room temperature for the x = 0.06 sample was 0.8581 emu/g.