Artificial spin ice arrays of micromagnetic islands are a means of engineering additional energy scales and frustration into magnetic materials. Despite much progress in elucidating the properties of such arrays, the `spins' in the systems studied so far have no thermal dynamics as the kinetic constraints are too high. Here we address this problem by using a material with an ordering temperature near room temperature. By measuring the temperature dependent magnetization in different principal directions, and comparing with simulations of idealized statistical mechanical models, we confirm a dynamical `pre-melting' of the artificial spin ice structure at a temperature well below the intrinsic ordering temperature of the island material. We thus create a spin ice array that has real thermal dynamics of the artificial spins over an extended temperature range.
@article{arxiv.1108.1092,
title = {Melting artificial spin ice},
author = {Vassilios Kapaklis and Unnar B. Arnalds and Adam Harman-Clarke and Evangelos Th. Papaioannou and Masoud Karimipour and Panagiotis Korelis and Andrea Taroni and Peter C. W. Holdsworth and Steven T. Bramwell and Björgvin Hjörvarsson},
journal= {arXiv preprint arXiv:1108.1092},
year = {2012}
}