IISc team grows ultra-thin magnetic material at wafer scale

BENGALURU: In a development that could help future electronics become smaller and more efficient, researchers from IISc have found a way to grow ultra-thin magnetic materials over large surfaces, moving a step closer to real-world use.These materials, known as 2D magnetic materials, are only a few atoms thick but can still retain magnetic properties. This makes them useful for devices such as hard drives, sensors and emerging “spintronics” technologies that rely on electron spin rather than charge. However, until now, scientists could only produce them in tiny flakes, limiting their practical use. The IISc team, led by assistant professor Akshay Singh, has developed a method to grow these materials across centimetre-scale wafers, similar to those used in chip-making. Their work has been published in the journal Advanced Materials. Instead of peeling off thin layers from bulk material, a method suited only for lab experiments, the team used a technique called Physical Vapour Transport Deposition (PVTD), where the material is first vapourised and then allowed to settle as a thin film on a surface. The challenge was to ensure the material formed evenly without defects, as even minor disturbances can affect its magnetic properties.

To overcome this, the researchers made several changes to the process. They reduced excess heat and light inside the growth chamber, pushed carrier gas flow rates far beyond what is conventionally used, and carefully controlled the supply of material during growth. They also removed oxygen and moisture, which can damage such sensitive materials.A key finding was the choice of surface. After testing different options, the team found that synthetic mica worked best, allowing the material to form smooth, well-ordered layers. The researchers were also able to transfer these films onto other surfaces, an important step for integrating them into electronic devices.The team says the method could be extended to other sensitive materials as well, opening up possibilities for new kinds of electronic and data storage technologies.