Magneto-Electric Control of Surface Anisotropy and Nucleation Modes in L1₀-CoPt Thin Films

Authors

• Priyanka Manchanda, University of Nebraska-LincolnFollow
• Pankaj Kumar, Indian Institute of Technology Mandi
• Hans Fangohr, University of Southampton
• David J. Sellmyer, University of Nebraska-LincolnFollow
• Arti Kashyap, Indian Institute of Technology MandiFollow
• Ralph Skomski, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2014

Citation

IEEE Magnetics Letters 5 (2014)

Abstract

The interplay between electric field-controlled surface magnetic anisotropy and micromagnetic nu-cleation modes for L1₀-CoPt thin films is investigated with density-functional and micromagnetic model calculations. The electric field redistributes electron states near the Fermi level, which has a fairly strong effect on the surface anisotropy, but due to inversion symmetry, the net anisotropy of the films with odd numbers of layers remains unchanged. By contrast, the micromagnetic nucleation mode is spatially asymmetric even for symmetric thin films with odd numbers of layers. This leads to a reduction of the nucleation field (coercivity) and—for suitably chosen nanostructures—to sub-stantial changes in the hysteretic behavior. In the lowest order, the coercivity reduction is independ-ent of the total film thickness. This counterintuitive feature can potentially be exploited in magneto-electric switching devices.