Crystal Structure and Bonding Analysis of (La0.8Ca0.2)(Cr0.9−x Co0.1Cu x )O3 Ceramics

Abstract

Abstract In this article, structural properties and bonding behaviours of codoped lanthanum chromites (La0.8Ca0.2)(Cr0.9−x Co0.1Cu x )O3 (x=0.00, 0.03, and 0.12) were investigated in detail. Polycrystalline chromite samples (La0.8Ca0.2)(Cr0.9−x Co0.1Cu x )O3 (x=0.00, 0.03, and 0.12) were prepared by a standard solid-state reaction process. The synthesised samples were characterised for their structural, morphological, optical, and magnetic properties using powder XRD, SEM/EDS, UV–Vis, and VSM. XRD data showed that the samples were crystallised into a single phase with orthorhombic structure. Powder profile refinement analysis suggested the reduction in lattice parameters and cell volume with the addition of Cu. The electron density distributions and the bonding features of the prepared samples have been investigated using maximum entropy method (MEM). The mid bond electron density values revealed the enhancement of ionic nature between lanthanum and oxygen ions and a reduction in covalent nature between chromium and oxygen ions. Heterogeneous distribution of particles with different sizes was observed through SEM micrographs. EDS spectra confirms the presence of constituent elements in the prepared samples. Optical band gap values are decreasing with the addition of Cu. Antiferromagnetic ordering was observed from M–H curves obtained at room temperature. The structural and the magnetic properties are correlated.