In the quest for more efficient and sensitive magnetic sensors, researchers have long been fascinated by the extraordinary magnetoresistance (EMR) effect. This phenomenon, which occurs when the current redistribution inside a hybrid metal-semiconductor device changes under an external magnetic field, has the potential to revolutionize various industries, including energy. However, until now, the impact of device topography on EMR performance has remained largely unexplored. A groundbreaking study published in JPhys Materials, the Journal of Physics Materials, is set to change that.
At the heart of this research is Sreejith Sasi Kumar, a scientist from the Department of Energy Conversion and Storage at the Technical University of Denmark. Kumar and his team have delved into the intricate world of EMR devices, focusing on how their physical topography can influence performance. “We’ve always assumed that these devices are flat, two-dimensional structures,” Kumar explains. “But in reality, they have significant topography that can affect their magnetoresistance.”
To understand these effects, the team created a 3D finite element model of concentric circular EMR devices with varying topographies. Their findings are nothing short of remarkable. They discovered that EMR devices with metal top contacts, which are easier to fabricate, perform similarly to conventional EMR devices where the metal shunt is embedded. For InSb/Au devices, both types achieved an impressive magnetoresistance of 490,000% at just 1 Tesla.
But the insights don’t stop there. The study also revealed that magnetoresistance increases with the thickness of the metal layer over a wide range of thicknesses. Moreover, the team found that a thicker shunt with thinner sidewalls outperforms the opposite configuration. “This could significantly simplify the fabrication process,” Kumar notes, “making these devices more accessible and cost-effective for commercial applications.”
So, what does this mean for the energy sector? Magnetic sensors are crucial for various applications, from power generation and distribution to renewable energy integration. More sensitive and efficient EMR devices could lead to improved monitoring and control systems, enhancing overall energy efficiency. As Kumar puts it, “The potential is immense. We’re just scratching the surface of what these devices can do.”
The research published in JPhys Materials, the Journal of Physics Materials, opens up new avenues for optimizing EMR devices. By considering the topography, manufacturers can potentially create more efficient and cost-effective sensors. As the energy sector continues to evolve, these advancements could play a pivotal role in shaping a more sustainable future. The work of Kumar and his team is a testament to the power of innovative thinking and meticulous research, pushing the boundaries of what’s possible in the world of magnetic sensors.
