Observation and elimination of broken symmetry in L1{sub 0} FePt nanostructures

Journal Article · Mon Dec 07 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4936933· OSTI ID:22486192

Quarterman, P.; Wang, Hao; Qiu, Jiao-Ming; Ma, Bin; Liu, Xiaoqi; Wang, Jian-Ping ^[1]; Guo, Honghua ^[2]

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1. Department of Electrical and Computer Engineering and the Center for Micromagnetics and Information Technologies (MINT), University of Minnesota, Minnesota 55455 (United States)
2. Department of Optical Science and Engineering, Fudan University, Shanghai (China)

An unexplained surface anisotropy effect was observed and confirmed in the magnetization reversal process of both L1{sub 0} phase FePt nanoparticles with octahedral shape and (001) textured L1{sub 0} FePt thin films with island nanostructures. We suggest that the nature of the observed surface effect is caused by broken symmetry on the FePt surface, which results in weakened exchange coupling for surface atoms. Furthermore, we propose, and experimentally demonstrate, a method to repair the broken symmetry by capping the FePt islands with a Pt layer, which could prove invaluable in understanding fundamental limitations of magnetic nanostructures.

• OSTI ID: 22486192
• Journal Information: Applied Physics Letters, Vol. 107, Issue 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
COUPLING
LAYERS
MAGNETIZATION
NANOPARTICLES
NANOSTRUCTURES
SURFACES
SYMMETRY BREAKING
THIN FILMS