Origin of reduced magnetization and domain formation in small magnetite nanoparticles

Zlatko Nedelkoski; Demie Kepaptsoglou; Leonardo Lari; Tianlong Wen; Ryan A Booth; Samuel D Oberdick; Pedro L Galindo; Quentin M Ramasse; Richard F L Evans; Sara Majetich; Vlado K Lazarov

doi:10.1038/srep45997

Origin of reduced magnetization and domain formation in small magnetite nanoparticles

Sci Rep. 2017 Apr 10:7:45997. doi: 10.1038/srep45997.

Authors

Affiliations

¹ Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
² SuperSTEM, Sci-Tech Daresbury Campus, Daresbury, WA4 4AD, UK.
³ Physics Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
⁴ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, China.
⁵ Department of Computer Science and Engineering, Universidad de Cádiz, 11510 Puerto Real, Spain.

Abstract

The structural, chemical, and magnetic properties of magnetite nanoparticles are compared. Aberration corrected scanning transmission electron microscopy reveals the prevalence of antiphase boundaries in nanoparticles that have significantly reduced magnetization, relative to the bulk. Atomistic magnetic modelling of nanoparticles with and without these defects reveals the origin of the reduced moment. Strong antiferromagnetic interactions across antiphase boundaries support multiple magnetic domains even in particles as small as 12-14 nm.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.