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Dataset associated with "Vogel-Fulcher-Tammann Freezing of a Thermally Fluctuating Artificial Spin Ice Probed by X-ray Photon Correlation Spectroscopy"

Morley, SA and Alba-Venero, D and Porro, Jose Maria and Riley, ST and Stein, A and Steadman, P and Stamps, RL and Langridge, Sean and Marrows, CH (2017) Dataset associated with "Vogel-Fulcher-Tammann Freezing of a Thermally Fluctuating Artificial Spin Ice Probed by X-ray Photon Correlation Spectroscopy". University of Leeds. [Dataset] https://doi.org/10.5518/59

Dataset description

We report on the crossover from the thermal to athermal regime of an arti cial spin ice formed from a square array of magnetic islands whose lateral size, 30 nm 70 nm, is small enough that they are superparamagnetic at room temperature. We used resonant magnetic soft x-ray photon correlation spectroscopy (XPCS) as a method to observe the time-time correlations of the uctuating magnetic con gurations of spin ice during cooling, which are found to slow abruptly as a freezing temperature T0 = 178 5 K is approached. This slowing is well-described by a Vogel-Fulcher-Tammann law, implying that the frozen state is glassy, with the freezing temperature being commensurate with the strength of magnetostatic interaction energies in the array. The activation temperature, TA = 40 10 K, is much less than that expected from a Stoner-Wohlfarth coherent rotation model. Zero- eld-cooled/ eld-cooled magnetometry reveals a freeing up of uctuations of states within islands above this temperature, caused by variation in the local anisotropy axes at the oxidised edges. This Vogel-Fulcher-Tammann behavior implies that the system enters a glassy state on freezing, which is unexpected for a system with a well-defined ground state.

Subjects: F000 - Physical sciences
F000 - Physical sciences > F300 - Physics > F340 - Mathematical & theoretical physics > F341 - Electromagnetism
Divisions: Faculty of Engineering and Physical Sciences > School of Electronic and Electrical Engineering
Faculty of Engineering and Physical Sciences > School of Physics and Astronomy
Related resources:
LocationType
http://doi.org/10.1103/PhysRevB.95.104422Publication
License: Creative Commons Attribution 4.0 International (CC BY 4.0)
Date deposited: 02 Jun 2017 09:31
URI: http://archive.researchdata.leeds.ac.uk/id/eprint/151

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