Soft x-ray zone plate microscopy has proven to be a valuable imaging technique for nanoscale studies. It complements
nano-analytic techniques such as electron and scanning probe microscopies. One of its key features is high spatial
resolution. We developed an overlay nanofabrication process which allows zone plates of sub-20 nm zone widths to be
fabricated. Zone plates of 15 nm outer zones were successfully realized using this process, and sub-15 nm resolution
was achieved with these zone plates. We extend the overlay process to fabricating zone plates of 12 nm outer zones,
which is expected to achieve 10 nm resolution. In addition, we have identified a pathway to realizing sub-10 nm
resolution, high efficiency zone plates with tilted zones using the overlay process.
We report our direct observation of the Barkhausen avalanche in ferromagnetic thin film systems, where a collective spin behavior produces nontrivial fluctuations in magnetization change under an external magnetic field.
For this study, we develop and use two direct full-field magnetic imaging techniques: magneto-optical microscope magnetometer (MOMM) and magnetic transmission X-ray microscopy (MTXM).
From a direct visualization and a statistical analysis of the fluctuating domain images for Co thin films, we investigate the scaling behavior of the Barkhausen avalanche both on spatial and temporal scales using MOMM.
We also investigate the reproducibility of the Barkhausen avalanche process.
Interestingly, the partially stochastic nucleation behavior is observed for CoCrPt alloy films by means of MTXM on a nanometer scale comparable to the fundamental length scales such as the Barkhausen volume and the grain size of the polycrystalline films.
Via these direct full-field observation techniques, dynamic details of Barkhausen avalanche are revealed.