IISc Scientists Develop Smart Materials That Switch Magnetic States with Light, Heat or Pressure
Researchers at the Indian Institute of Science (IISc) in Bengaluru have created a new class of 'smart' materials capable of changing their magnetic properties when exposed to light, heat, or pressure. This breakthrough could pave the way for more sensitive industrial sensors, energy-efficient data storage, and future quantum technologies.
The findings, detailed in two separate studies, describe porous crystalline materials that can reversibly switch between magnetic and non-magnetic states without degrading over repeated cycles. The ability to reverse this change makes the materials suitable for repeated use in practical devices.
The research, led by Associate Professor Abhishek Mondal from the Solid State and Structural Chemistry Unit (SSCU), addresses a long-standing challenge in materials science. Existing porous materials used for sensing gases or liquids often fail to switch their magnetic state uniformly because the change remains confined to a small region.
The IISc team overcame this by designing a highly porous material with an elastic internal structure. When one atom changes its magnetic state, it triggers neighbouring atoms to do the same, creating a domino effect that spreads throughout the material.
'In addition to mechanical pressure, light and heat can also stimulate the spin state switch reversibly, allowing the material to be used repeatedly,' the researchers said.
Mondal noted that they are already exploring practical applications. 'We're working on scaling up the complex to design smart gas-capture sensors that can selectively adsorb industrially critical gases like methane, carbon monoxide, and carbon dioxide with supreme sensitivity,' he said.
The second study tackles another major hurdle: temperature. Many materials with similar properties currently work only at extremely low temperatures, making them expensive and impractical outside laboratory settings.
'Our goal was to synthesise a chemical system that exhibits these transitions near ambient temperatures. Contemporary materials often operate only at ultra-low temperatures below 50 K (-223°C). They are highly volatile and relax back to their ground state with even a slight rise in temperature,' said Krishna Kaushik, a PhD student and first author of both studies.
The new material functions close to room temperature and also changes colour as it switches between magnetic states, making the transformation visible to the naked eye.
Mondal added: 'Although these discoveries are still at the fundamental research stage, they address important global challenges. Modern data centres and electronic devices consume enormous amounts of energy. Developing alternative materials that operate more efficiently could reduce energy demands and contribute to more sustainable technologies.'
He pointed out that materials capable of acting as sensors, switches, and memory elements simultaneously could simplify electronic devices and reduce manufacturing costs.
