Functional materials are advanced materials engineered for specific purposes due to their unique intrinsic properties. They are widely used in electronic devices for applications such as magnetic, magnetocaloric, magnetoelastic, spintronic, optical, catalytic, thermometric, ferroelectric, piezoelectric, and dielectric functionalities. These materials play a key role in energy-efficient systems, sensing, energy conversion, actuation, and computation. One of their most remarkable features is tunability in response to external stimuli, including electromagnetic radiation, mechanical stress, temperature changes, magnetic fields, and electric fields. This responsiveness opens up a broad range of potential applications across technology and industry.