Dopant incited alterations in structural, morphological, optical, and dielectric properties of Er-doped LaCrO_3

摘要

The crystalline samples of La_(1-x)Er_xCrO_3 0 = 0.0, 0.2, 0.4, 0.6) system have been synthesized through the sol-gel process. The XRD pattern of the pristine LaCrO_3 displays the single-phase characteristics having orthorhombic crystal structure with Pnma space group. On the other hand, the Er-doped samples exhibit the mixed-phase attributes of both parent and ErCrO_3 compounds. The structural alteration from LaCrO_3 to ErCrO_3 increases with the increase in doping content. The escalation in the Er doping amount leads to a decline in the crystallite size and unit cell volume. TEM analysis verifies that the particle size reduces from 423 to 328 nm, as the content of Er in the crystal lattice is increased. The UV/Vis spectroscopy specifies that the energy band gap (E_g) values rise slightly with the increment in the doping quantity of Er in the LaCrO_3. The Urbach energy is also found to increase in the doped samples. The effect of Er doping on optical constants namely refractive index, extinction coefficient, and optical conductivity has been investigated. The study on dielectric parameters infers that the dielectric constant and loss tangent (tanδ) display the typical dispersive behavior attributed to the Maxwell-Wagner interfacial polarization. These samples follow the UDR model only in the high-frequency regime. The electric modulus exploration ascertained that grains are mainly involved in the conduction process in these samples. The frequency-dependent ac conductivity plot indicated that these samples follow the Jonscher empirical power law in the given frequency range.