Integrating Experimental and Computational Insights: A Dual Approach to Ba2CoWO6 Double Perovskites

• Published in: Ceramics 2024-12, Vol.7 (4), p.2006-2023
• Main Authors: Raji, Ramesh Kumar, Ramachandran, Tholkappiyan, Dhilip, Muthu, Aravindan, Vivekanandan, Punitha, Joseph Stella, Hamed, Fathalla
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Ba2CoWO6 double perovskites; Barium; Catalysis; Ceramics; Cobalt; Computational study; Crystal lattices; Crystal structure; Crystallites; Cubic lattice; Current carriers; Dielectric properties; Efficiency; electrical and magnetic properties; Electrocatalysis; Electron microscopy; Electronic properties; Electronic structure; Electrons; Energy storage; First principles; Investigations; Light emitting diodes; Magnetic devices; Magnetic measurement; Magnetic properties; Morphology; Optical properties; Oxygen ions; Perovskites; Photocatalysis; Photoelectrons; Photoluminescence; Rietveld refinement; Room temperature; Spectrum analysis; Structural analysis; Synthesis; Temperature; Transmission electron microscopy; Valence; X-ray Photoelectron Spectroscopy (XPS)
• ISSN: 2571-6131; 2571-6131
• DOI: 10.3390/ceramics7040125

Double perovskite materials have emerged as key players in the realm of advanced materials due to their unique structural and functional properties. This research mainly focuses on the synthesis and comprehensive characterization of Ba2CoWO6 double perovskite nanopowders utilizing a high-temperature conventional solid-state reaction technique. The successful formation of Ba2CoWO6 powders was confirmed through detailed analysis employing advanced characterization techniques. Rietveld refinement of X-ray diffraction (XRD) and Raman data established that Ba2CoWO6 crystallizes in a cubic crystal structure with the space group Fm-3m, indicative of a highly ordered perovskite lattice. The typical crystallite size, approximately 65 nm, highlights the nanocrystalline nature of the material. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) discovered a distinctive morphology characterized by spherical shaped particles, suggesting a complex particle formation process influenced by synthesis conditions. To probe the electronic structure, X-ray Photoelectron Spectroscopy (XPS) identified cobalt and tungsten valence states, critical for understanding dielectric properties associated with localized charge carriers. The semiconducting character of the synthesized Ba2CoWO6 nanocrystalline material was confirmed through UV-Visible analysis, which revealed an energy bandgap value of 3.3 eV, which aligns well with the theoretical predictions, indicating the accuracy and reliability of the experimental results. The photoluminescence spectrum exhibited two distinct emissions in the blue-green region. These emissions were attributed to the transitions 3P0→3H4, 3P0→3H5, and 3P0→3H6, primarily resulting from the contributions of Ba2+ ions. The dielectric characteristics of the compound were analyzed across a different range of frequencies, spanning from 1 kHz to 1 MHz. Magnetic characterization using Vibrating Sample Magnetometry (VSM) revealed antiferromagnetic behavior of Ba2CoWO6 ceramics at room temperature, attributed to super-exchange interactions between Co3+ and W5+ ions mediated by oxygen ions in the perovskite lattice. Additionally, first-principles calculations based on the Generalized Gradient Approximation (GGA+U) with a modified Becke–Johnson (mBJ) potential were employed to gain a deeper understanding of the structural and electronic properties of the materials. This approach involved systematically varying the Hubbard U parameter to op