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

Journal Article · Tue Sep 08 00:00:00 EDT 2015 · Proceedings of SPIE - The International Society for Optical Engineering

DOI:https://doi.org/10.1117/12.2189320· OSTI ID:1246787

Drouhin, Henri-Jean; Wegrowe, Jean-Eric; Razeghi, Manijeh; Morley, Sophie A.; Stein, Aaron; Rosamond, Mark C.; Alba Venero, Diego; Hrabec, Aleš; Shepley, Philippa M.; Im, Mi-Young; Fischer, Peter; Bryan, Matthew T.; Allwood, Dan A.; Steadman, Paul; Langridge, Sean; Marrows, Christopher H.

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 the analysis of vertex population during reversal.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC00112704
• OSTI ID: 1246787
• Report Number(s): BNL-111860-2016-JA; KC0403020
• Journal Information: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 9551, Issue 9551; Conference: San Diego, CA (United States), 9-13 Aug 2015; ISSN 0277-786X
• Publisher: SPIE
• Country of Publication: United States
• Language: English

Related Subjects

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