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Title: Temperature and magnetic-field driven dynamics in artificial magnetic square ice

Artificial spin ices are often spoken of as being realisations of some of the celebrated vertex models of statistical mechanics, where the exact microstate of the system can be imaged using advanced magnetic microscopy methods. The fact that a stable image can be formed means that the system is in fact athermal and not undergoing the usual finite-temperature fluctuations of a statistical mechanical system. In this paper we report on the preparation of artificial spin ices with islands that are thermally fluctuating due to their very small size. The relaxation rate of these islands was determined using variable frequency focused magneto-optic Kerr measurements. We performed magnetic imaging of artificial spin ice under varied temperature and magnetic field using X-ray transmission microscopy which uses X-ray magnetic circular dichroism to generate magnetic contrast. Furthermore, we have developed an on-membrane heater in order to apply temperatures in excess of 700 K and have shown increased dynamics due to higher temperature. Due to the ‘photon-in, photon-out' method employed here, it is the first report where it is possible to image the microstates of an ASI system under the simultaneous application of temperature and magnetic field, enabling the determination of relaxation rates, coercivties, and themore » analysis of vertex population during reversal.« less
Authors:
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Publication Date:
Report Number(s):
BNL-111860-2016-JA
Journal ID: ISSN 0277-786X; KC0403020
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Proceedings of SPIE - The International Society for Optical Engineering
Additional Journal Information:
Journal Volume: 9551; Journal Issue: 9551; Conference: San Diego, CA (United States), 9-13 Aug 2015; Journal ID: ISSN 0277-786X
Publisher:
SPIE
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; magnetism; microscopy; photons; x-ray magnetic circular dichroism; X-rays; magneto-optics; mechanics; artificial spin ice; vertex model; nanomagnetism; magnetic soft X-ray; transmission microscopy
OSTI Identifier:
1246787