In the heart of India, researchers are unraveling the mysteries of magnetic thin films, and their findings could send ripples through the energy sector. Subrata Sarkar, a physicist from the Department of Physics at the Central Institute of Technology Kokrajhar, has been leading a team exploring the magnetic properties and electrical characteristics of cobalt-nickel multilayers. Their work, published in the journal ‘MetalMat’ (translated to English as ‘Metal Materials’), could pave the way for more efficient energy devices.
The team fabricated thin films of cobalt and nickel, each just a few atoms thick, under various conditions. They experimented with different underlayers and annealing treatments, which involve heating the materials to alter their properties. The results were intriguing. “The as-prepared films showed isotropic behavior, meaning their magnetic properties were the same in all directions,” Sarkar explains. “But when we introduced underlayers or annealing treatments, the films exhibited in-plane magnetic anisotropy, where properties vary depending on the direction within the plane.”
This magnetic anisotropy is crucial for many energy applications, as it allows for more precise control of magnetic fields. The team also observed variations in saturation magnetization and coercivity—the force needed to demagnetize the material—depending on the preparation conditions. “The films with Ta/Cu underlayer in situ annealing followed by post-annealing exhibited the highest coercivity,” Sarkar notes. “This could be particularly useful for applications requiring strong magnetic fields.”
But the team’s findings didn’t stop at magnetic properties. They also examined the electrical characteristics of the films, discovering diode-like behavior with varying breakdown voltages. “The breakdown voltage ranged from 14 to 58 volts, depending on the preparation conditions,” Sarkar says. This behavior is vital for energy storage and conversion devices, where controlling electrical flow is paramount.
So, what does this mean for the energy sector? The ability to tailor magnetic and electrical properties of thin films could lead to more efficient power generation, storage, and conversion devices. Imagine solar panels that convert more sunlight into electricity, or batteries that store more energy and last longer. These are just a few potential applications of the research.
Moreover, the team’s findings could inspire further research into magnetic thin films, driving innovation in the energy sector. “Our work is just the beginning,” Sarkar says. “There’s so much more to explore in this field.”
As we grapple with the challenges of climate change and energy sustainability, research like Sarkar’s offers a glimmer of hope. By unraveling the mysteries of magnetic thin films, we’re one step closer to a cleaner, greener future. And that’s something we can all get behind.