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

Authors

• Balamurugan Balasubramanian, University of Nebraska–LincolnFollow
• Priyanka Manchanda, University of Nebraska-LincolnFollow
• Ralph A. Skomski, University of Nebraska-LincolnFollow
• Pinaki Mukherjee, University of Nebraska-LincolnFollow
• Shah R. Valloppilly, University of Nebraska-LincolnFollow
• Bhaskar Das, University of Nebraska-LincolnFollow
• George C. Hadjipanayis, University of DelawareFollow

Document Type

Article

Date of this Version

2016

Citation

APPLIED PHYSICS LETTERS 108, 152406 (2016)

http://dx.doi.org/10.1063/1.4945987

Comments

Copyright 2016 AIP Publishing LLC.

Abstract

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.