In the realm of materials science, a groundbreaking discovery has emerged from the labs of the Academy of Scientific and Innovative Research (AcSIR) in Ghaziabad, India, and the CSIR-National Physical Laboratory in New Delhi. Led by Dr. N K Karn, a team of researchers has successfully synthesized single crystalline gray-arsenic (As) using the Bismuth flux method. This isn’t just any crystal; it’s a material that could revolutionize the energy sector with its unique topological properties.
The journey began with the synthesis of high-quality gray-arsenic crystals. Using X-ray diffraction (XRD), the team confirmed the single-phase nature of the crystals, which exhibited a rhombohedral structure with the space group R-3m. The sharp XRD peaks on mechanically exfoliated thin flakes indicated exceptional crystallinity, with growth aligned along the c-axis. Energy Dispersive X-ray Analysis (EDAX) further validated the stoichiometric purity of the as-grown As single crystal.
But the real magic lies in the material’s electronic and magneto-transport properties. The resistivity versus temperature (ρ-T) measurements showed that gray-arsenic maintains its metallic nature from 300 K down to 2 K, with a residual resistivity ratio (ρ_300K / ρ_2K) of 180. This high metallic nature is a testament to the quality of the synthesized crystal.
The true excitement, however, comes from the magneto-transport measurements. At 2 K and 14 Tesla transverse magnetic fields, the material exhibited a colossal magneto-resistance (MR) of 10^4%, along with Shubnikov-de Haas (SdH) oscillations. These oscillations are a clear indication of the presence of topological surface states, which are crucial for potential applications in spintronics and quantum computing.
Dr. Karn elaborates, “The non-trivial band topology and edge states in As are confirmed by first principle calculations. The Z2 invariant value (1,111) calculated by Wilson’s loop method affirms As to be a strong topological insulator (TI).”
The implications of this discovery are vast, particularly for the energy sector. Topological insulators like gray-arsenic could pave the way for more efficient and robust electronic devices, potentially reducing energy losses and enhancing the performance of electronic components. This could lead to significant advancements in energy storage, transmission, and conversion technologies.
The research, published in Materials Research Express, which is known as the Materials Research Express, highlights the potential of gray-arsenic as a strong topological insulator. The study not only advances our understanding of topological materials but also opens new avenues for their application in cutting-edge technologies. As we delve deeper into the quantum realm, materials like gray-arsenic could very well be the cornerstone of future technological innovations, shaping the landscape of the energy sector and beyond.
