We review models for the nucleation of magnetisation reversal, i.e. the formation of a region of reversed magnetisation in an initially magnetically saturated system. For small particles models for collective reversal, either uniform (Stoner-Wohlfarth model) or non-uniform like curling give good agreement between theory and experiment. For microscopic objects and thin films, we consider two mod...

We study vortex clustering in type II Superconductors. We demonstrate that the “second peak” observed in magnetisation loops may be a dynamical effect associated with a density driven instability of the vortex system. At the microscopic level the instability shows up as the clustering of individual vortices at (rare) preferential regions of the pinning potential. In the limit of quasi-static ra...

Magnetic nanoparticles are complex mesoscopic systems which have unique physical properties that clearly differ from those of atoms and bulk materials. They find numerous technological applications ranging from ultra-high-density recording media (Bader, 2006) to biomedicine (Pankhurst et al., 2003). The necessity to reduce the size of the nanoparticles for these applications have raised a key i...

A simple trinuclear dysprosium complex shows complex slow relaxation of the magnetisation.

In this study, we report on a new approach for remote temperature probing that provides accuracy as good as 0.017°C (0.0055% accuracy) by measuring the magnetisation curve of magnetic nanoparticles. We included here the theoretical model construction and the inverse calculation method, and explored the impact caused by the temperature dependence of the saturation magnetisation and the applied m...

We obtain the persistence exponents for an antiferromagnetic Ising system in which the magnetisation is kept constant. This system belongs to Model C (system with non-conserved order parameter with a conserved density) and is expected to have persistence exponents different from that of Model A (system with no conservation) but independent of the conserved density. Our numerical results for bot...

We describe how the compliance requirements for data retention from recent laws such as the US Sarbanes Oxley Act may be supported by a tamper-evident secure storage system based on probe storage with a patterned magnetic medium. This medium supports normal read/write operations by out-of-plane magnetisation of individual dots. We report on an experiment to show that in principle the medium als...

Two-dimensional (13)C-(13)C correlation experiments are widely employed in structure determination of protein assemblies using solid-state nuclear magnetic resonance. Here, we investigate the process of (13)C-(13)C magnetisation transfer at a moderate magic-angle-spinning frequency of 30 kHz using some of the prominent second-order dipolar recoupling schemes. The effect of isotropic chemical-sh...

We propose a tamper-evident storage system based on probe storage with a patterned magnetic medium. This medium supports normal read/write operations by outof-plane magnetisation of individual magnetic dots. We report on measurements showing that in principle the medium also supports a separate class of write-once operation that destroys the out-of-plane magnetisation property of the dots irrev...