Causal analysis and visualization of magnetization reversal using feature extended landau free energy.

The magnetization reversal in nanomagnets is causally analyzed using an extended Landau free-energy model. This model draws an energy landscape in the information space using physics-based features. Thus, the origin of the magnetic effect in macroscopic pinning phenomena can be identified.

Accelerating small-angle scattering experiments on anisotropic samples using kernel density estimation.

We propose a method to accelerate small-angle scattering experiments by exploiting spatial correlation in two-dimensional data. We applied kernel density estimation to the average of a hundred short scans and evaluated noise reduction effects of kernel density estimation (smoothing). Although there is no advantage of using smoothing for isotropic data due to the powerful noise reduction effect of radial averaging, smoothing with a statistically and physically appropriate kernel can shorten measurement time by less than half to obtain sector averages with comparable statistical quality to that of sector averages without smoothing.

Reconstruction of magnetic domain structure using the reverse Monte Carlo method with an extended Fourier image.

Visualization of the magnetic domain structure is indispensable to the investigation of magnetization processes and the coercivity mechanism. It is necessary to develop a reconstruction method from the reciprocal-space image to the real-space image. For this purpose, it is necessary to solve the problem of missing phase information in the reciprocal-space image.

Electron magnetic resonance in interacting ferromagnetic-metal nanoparticle systems: experiment and numerical simulation.

We have studied electron magnetic resonance (EMR) in ferromagnetic-metal nanoparticle systems which show promise as a component of left-handed metamaterials. Metallic Ni nanoparticles of about 8 nm in diameter are embedded in polymer films. When the average distance between the nanoparticles is decreased, we observed that the EMR signal shifts and broadens.