Research Projects

Develop and understand a fundamental correlation between structural aspects of the switchable magnetic molecules and their integration into various host matrices in pursuit of fabricating hybrid smart materials having potential applications in optical and electrical sensors, field transistors, mechanical actuators, etc. Spin Crossover (SCO) complexes, also known as switchable magnetic molecules, display magnetic bistability between two stable magnetic states, and have the ability to be controllably and reversibly tuned using various triggers, such as temperature, pressure, magnetic or electric fields, and even light. These are mostly the Fe(II) base complexes, and during spin transition between t2g and eg electronic levels, the bond lengths of the complex change and impact the physical properties of the materials. Originally, their application potential was envisioned in data processing and recording, since the molecular switching can significantly increase the capacity and reduce the size of electronic devices. Recently the application potential of these complexes is reinvented towards advanced optical materials (due the change in their refractive index), electrical materials (due change into their polarization), thermometric sensors (due to very accurate change into their colour) etc. during the spin state switching. This project is a combination of two components, advances in the design synthesis as well in the applications in smart materials. For example, in the first objective, we have proposed a design of chiral cage complexes of Fe(II) and tuning of the spin state of the metal centre based on the chiral recognition/complementarity of guest fit. In the next objective, I proposed the design synthesis of polar crystals that show thermal or photo-induced directional electron transfer, and using this property, the engineering of thermally- and photo-induced ferroelectric materials. The LIESST (switching from LS to HS) and reverse LIESST (switching from HS to LS) study by alternating different wavelengths of light and their dynamics will be studied with the promise to design of molecular magnetic materials with switchable bistable states. We are also interested in finding out the possibility of reversibly producing or eliminating the magnetic hysteresis, AC signal of a molecular magnet when the LIESST switches the spin state, as well as the anisotropy of a metal center and the magnetic coupling between them. This is a very new concept, and not much work is done in this direction. Therefore, the LIESST and reverse LIESST experiments may provide a new type of switchable bistable system that exhibits opposite polarization directions of their magnetic moment, which is crucial for future technological demands for high-density data storage and processing. In another objective, we will focus on the integration of these molecules into hybrid materials for easy handling into different shapes and sizes for device design. Some of the device characterization will be done in collaboration with colleagues from the Electrical Engineering and Computer Science Department (e.g., for electrical characterization) and the Physics Department (for THz spectroscopy), IISER Bhopal.