Octahedral distortion induced changes in phonon vibration, optical and dielectric properties of xLaAlO3 – (1-x)Ba(Mg1/2 Mo1/2 )O3

The microstructural, vibrational, optical and impedance spectroscopy of x LaAlO ₃ –(1- x )Ba(Mg _1/2 Mo _1/2 )O ₃ [LA-BMM] have been investigated for various values of x . Rhombohedral \(\:R\stackrel{-}{3}C\:\)(161) phases for LA and cubic \(\:Fm3m\) (225) phases for BMM are revealed by the Refinement of X-ray diffraction (XRD) patterns using Rietveld method for all values of x . XRD patterns demonstrate that the rhombohedral phase systematically increases and the cubic phase systematically decreases with increase of doping concentration x . Several vibrational phonon modes have been identified from the samples room-temperature comparative Raman spectra by group theoretical studies in addition with experimental literature review. Samples band-gaps were gradually decreases from 5.86 eV to 3.96 eV as concentration x increases from 0.10 to 0.90. An LCR meter instrument (Hioki-3532-50, Japan) was used to measure the dielectric data from 300 K to 673 K in the range of frequencies from 50 Hz to 4.8 MHz According to dielectric data, conductivity at room temperature increases when doping concentration x increases.