Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 250, 303 (2006)
Radiation Effects in Insulators – Proceedings of the 13th International Conference on Radiation Effects in Insulators (REI-2005)

D. Spemann, K. Schindler, P. Esquinazi, M. Diaconu, H. Schmidt, R. Höhne, A. Setzer and T. Butz

Abstract

In this study, ferromagnetic microstructures in highly oriented pyrolytic graphite and superparamagnetic spots in polyimide foils were created by 2.25 MeV proton microbeam irradiation and characterized using atomic and magnetic force microscopy. For this purpose, graphite samples were irradiated with cross-like patterns of 15 μm × 15 μm size using ion fluences in the range of (0.003–2.5) × 10¹⁸ cm⁻². The irradiated crosses showed strong magnetic signals and a complex domain structure in the magnetic images depending on the geometrical dimensions of the crosses. Furthermore, polyimide foils were irradiated with microspots and fluences in the range of (0.016–3.1) × 10¹⁹ cm⁻². Magnetic force microscopy shows very strong phase shifts in these irradiated areas.