Direct observation of magnetic vortex behavior in an ordered La0.7Sr0.3MnO3 dot arrays

Zhenghua Li; Dapeng Dong; Dedi Liu; Jia Liu; Dongping Liu; Xiang Li

doi:10.1039/c6cp04583a

Direct observation of magnetic vortex behavior in an ordered La_0.7Sr_0.3MnO₃ dot arrays

Phys Chem Chem Phys. 2016 Oct 12;18(40):28254-28261. doi: 10.1039/c6cp04583a.

Authors

Zhenghua Li¹, Dapeng Dong¹, Dedi Liu¹, Jia Liu¹, Dongping Liu¹, Xiang Li²

Affiliations

¹ Liaoning Key Lab of Optoelectronic Films & Materials, School of Physics and Materials Engineering, Dalian Nationalities University, Dalian, 116600, China. dongping.liu@dlnu.edu.cn.
² School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.

PMID: 27722330
DOI: 10.1039/c6cp04583a

Abstract

Directly observing the magnetic domain behavior in patterned nanostructures is crucial to the investigation into advanced spin-based devices. Herein, we show that the magnetic vortex behavior can be deterministically observed and controlled in highly spin polarized La_0.7Sr_0.3MnO₃ (LSMO) triangular dots by successive in-field magnetic force microscopy (MFM). Imaging the magnetic domains with MFM shows that most of the LSMO dots exhibit magnetic vortex states with a clockwise or anticlockwise "pinwheel" structure for decreasing the demagnetization energy. Probing the vortex chirality using in-field MFM indicates that the selective spin circulation of the triangular dots depends on the magnetic orientation of the bias nanomagnet with specially designed geometries. Comparison between measurement and simulation reveals that the vortex behavior should be governed by an interface involved pinning strength at the boundaries, as well as a geometrically induced shape anisotropy of the triangular dot, both of which result in shape-dominated magnetic domain reversals.