Research Projects

Double perovskites of the form A₂BB′O₆ have emerged as multifunctional materials that exhibit rich interactions between spin, lattice, and charge degrees of freedom. Among these, systems incorporating W (5d) and Te (5p) elements at the B′-site are of particular interest due to strong spin–orbit coupling and potential for novel spin–phonon and electronic interactions. However, these systems remain largely unexplored with regard to vibrational dynamics and correlated magnetic–electronic phenomena. This project aims to explore the fundamental mechanisms driving spin–phonon coupling and composition-induced property tuning in W/Te-enriched double perovskites, followed by the integration of these oxides with MXenes for energy-related applications. The central hypothesis is that W/Te-based double perovskites exhibit enhanced spin–phonon coupling and tunable electronic behavior owing to their unique orbital hybridization and spin–orbit interactions. These properties can be further tailored through A- and B-site compositional variation and interfacial engineering with MXene (Ti₃C₂Tₓ) nanosheets. The scientific objectives are: 1. Synthesize a systematic series of A₂(B)(W/Te)O₆ (A = Ba, Sr, Ca; B = Fe, Co, Mn) via sol-gel and solid-state methods. 2. Investigate structure, phase purity, cation ordering, and symmetry using XRD, Rietveld refinement, and Raman spectroscopy. 3. Probe spin–phonon coupling through temperature- and magnetic field-dependent Raman measurements (80–800 K, 0–9 T). 4. Perform first-principles DFT+U simulations to calculate phonon dispersion, Born effective charges, and electronic band structures. 5. Fabricate MXene–perovskite nanocomposites and analyze interfacial charge transfer via XPS. 6. Evaluate the energy storage behavior using cyclic voltammetry and charge–discharge tests. The main experiments will include magnetic and Raman spectroscopies to track phonon–spin coupling, theoretical modeling of phonon and electronic structures using DFT (VASP), and electrochemical characterization of MXene-based composites for capacitive storage. If successful, the project is expected to: • Reveal the microscopic origin of spin–lattice–electronic coupling in W/Te-based double perovskites. • Deliver DFT-validated design rules for multifunctional magnetic oxides. • Produce MXene–perovskite nanocomposites with improved energy storage characteristics. • Establish structure–property–function relationships with direct relevance to spintronics and future electronic materials. By integrating advanced vibrational spectroscopy, electronic structure theory, and composite material design, this project addresses both fundamental understanding and applied innovation in oxide electronics and energy materials.