High-coercivity magnetism in nanostructures with strong easy-plane anisotropy

Journal Article · 15 April 2016 · Applied Physics Letters

DOI: https://doi.org/10.1063/1.4945987 · OSTI ID:1470753

Balasubramanian, Balamurugan ^[1]; Manchanda, Priyanka ^[1]; Skomski, Ralph ^[1]; Mukherjee, Pinaki ^[1]; Valloppilly, Shah R. ^[2]; Das, Bhaskar  ^[1]; Hadjipanayis, George C. ^[3]; Sellmyer, David J. ^[1]

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1. Univ. of Nebraska, Lincoln, NE (United States). Nebraska Center for Materials and Nanoscience and Dept. of Physics and Astronomy
2. Univ. of Nebraska, Lincoln, NE (United States). Nebraska Center for Materials and Nanoscience
3. Univ. of Delaware, Newark, DE (United States). Dept. of Physics and Astronomy

Here, we report the fabrication of a rare-earth-free permanent-magnet material Co₃Si in the form of nanoparticles and investigate its magnetic properties by experiments and density-functional theory (DFT). The DFT calculations show that bulk Co₃Si has an easy-plane anisotropy with a high K₁ ≈ -64 Merg/cm³ (-6.4 MJ/m³) and magnetic polarization of 9.2 kG (0.92 T). In spite of having a negative anisotropy that generally leads to negligibly low coercivities in bulk crystals, Co₃Si nanoparticles exhibit high coercivities (17.4 kOe at 10K and 4.3 kOe at 300 K). This result is a consequence of the unique nanostructure made possible by an effective easy-axis alignment in the cluster-deposition method and explained using micromagnetic analysis as a nanoscale phenomenon involving quantum-mechanical exchange interactions.

• Research Organization: Univ. of Nebraska, Lincoln, NE (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); US Army Research Office (ARO); National Science Foundation (NSF)
• Grant/Contract Number: FG02-04ER46152; FG02-04ER4612; WF911NF-10-2-0099; NNCI: 1542182
• OSTI ID: 1470753
• Alternate ID(s): OSTI ID: 1247890
• Journal Information: Applied Physics Letters, Vol. 108, Issue 15; ISSN 0003-6951
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English