3D-Hydrogen analysis of ferromagnetic microstructures in proton irradiated graphite
Title of conference publication:
Proceedings of the Seventeenth International Conference on Ion Beam Analysis
Journal:
Nuclear Instruments and Methods in Physics Research Section B
Volume:
249
Issue:
1-2
Conference title:
International Conference on Ion Beam Analysis (17., 2005, Sevilla)
Venue:
Sevilla
Year of conference:
2005
Year:
2006
Pages from - to:
286-291
Language:
Englisch
Keywords:
Ferromagnetic carbon ; Highly oriented graphite ; 3D hydrogen microscopy ; Ion microbeam ; Ion implantation ; Hydrogen diffusion
Abstract:
Recently, magnetic order in highly oriented pyrolytic graphite (HOPG) induced by proton broad- and microbeam irradiation was discovered. Theoretical models propose that hydrogen could play a major role in the magnetism mechanism. We analysed the hydrogen distribution of pristine as well as irradiated HOPG samples, which were implanted to μm-sized spots as well as extended areas with various doses of 2.25 MeV protons at the Leipzig microprobe LIPSION. For this we used the sensitive 3D hydrogen microscopy system at the Munich microprobe SNAKE. The background hydrogen level in pristine HOPG is determined to be less than 0.3 at-ppm. About 4.8 × 1015 H-atoms/cm2 are observed in the near-surface region (4 μm depth resolution). The depth profiles of the implants show hydrogen located within a confined peak at the end of range, in agreement with SRIM Monte Carlo simulations, and no evidence of diffusion broadening along the c-axis. At the sample with microspots, up to 40 at. «
Recently, magnetic order in highly oriented pyrolytic graphite (HOPG) induced by proton broad- and microbeam irradiation was discovered. Theoretical models propose that hydrogen could play a major role in the magnetism mechanism. We analysed the hydrogen distribution of pristine as well as irradiated HOPG samples, which were implanted to μm-sized spots as well as extended areas with various doses of 2.25 MeV protons at the Leipzig microprobe LIPSION. For this we used the sensitive 3D hydrogen mi... »