Thermodynamics and magnetization reversal in artificial brickwork spin ice

The thermodynamics and magnetization reversal behavior of three artificial frustrated brickwork systems are investigated by means of the Monte Carlo method. Three frustrated systems have different array patterns of ferromagnetic nanoislands, and consequently different geometry symmetry and magnetic properties. The simulated results show that two brickwork systems which have only ‘three-spins’ vertex exhibit the long-range ordered magnetic ground state, and one brickwork system that contains mixed ‘two-spins’ and ‘four-spins’ vertex as well as ‘three-spins’ vertex has a high degeneracy of ground state and no long-range order. In all three frustrated systems, there occurs the phase transition from the magnetic ground order to disorder. Three frustrated brickwork lattices show significant differences in the reversal mechanism in the presence of magnetic field for different lattice spacings.