In the realm of energy materials research, a team of scientists from various institutions in Japan, including the University of Tokyo, Tohoku University, and the National Institute for Materials Science, has made a significant stride in understanding the behavior of bismuth, a material of interest in the energy sector due to its unique electronic properties. The researchers, led by Suguru Hosoi and including Fumu Tachibana, Mai Sakaguchi, Kentaro Ishida, Masaaki Shimozawa, Koichi Izawa, Yuki Fuseya, Yuto Kinoshita, and Masashi Tokunaga, have published their findings in the journal Nature Communications.
The study focuses on a phenomenon known as magnetoelastoresistance (MER), which is the change in electrical resistance of a material when it is subjected to both mechanical strain and a magnetic field. The researchers applied current, uniaxial stress, and magnetic field all along the binary axis of bismuth, a multivalley material, and observed how the MER varied with the magnetic field.
The magnitude of MER initially increased steeply at low magnetic fields, reached a peak, and then gradually decreased at higher fields. To understand this behavior, the researchers decomposed the strain response into symmetric and antisymmetric components. They found that the symmetric component remained nearly constant under magnetic fields, suggesting that the electronic properties of the valleys in bismuth are not significantly affected by strain, even in the presence of a magnetic field. This is a crucial finding as it indicates a rigid-band nature of the valleys in bismuth, which could be beneficial for stable electronic performance in energy devices.
On the other hand, the antisymmetric component, which is linked to mobility anisotropy, dominated the MER response in a magnetic field. At low magnetic fields, the applied field modified the apparent mobility of each valley, enhancing the magnitude of the antisymmetric MER. However, at higher fields, field-induced valley polarization altered this mobility anisotropy, leading to a moderate suppression of the MER. This understanding of the interplay between magnetic field, strain, and charge transport is fundamental for the development of advanced energy materials and devices.
The practical applications of this research in the energy sector are manifold. For instance, the ability to manipulate the electronic properties of materials like bismuth through strain and magnetic fields could lead to the development of more efficient and robust energy storage devices, sensors, and electronic components. Moreover, the symmetry-resolved MER technique demonstrated in this study provides a powerful tool for probing valley-dependent electronic states, which is essential for the design and optimization of next-generation energy materials.
In conclusion, the research conducted by Hosoi and his team sheds light on the complex behavior of bismuth under strain and magnetic fields, offering valuable insights for the energy industry. The findings, published in Nature Communications, pave the way for the development of advanced materials and devices that could revolutionize the energy sector.
This article is based on research available at arXiv.