Nanostructuring of FePt thin films by plasma focus device: pulsed ion irradiation dependent phase transition and magnetic properties

• Published in: Applied physics. A, Materials science & processing Vol. 96; no. 4; pp. 1027 - 1033
• Main Authors: Pan, Z. Y., Rawat, R. S., Lin, J. J., Zhang, T., Lee, P., Tan, T. L., Springham, S. V.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2009; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Ferrous alloys; Intermetallics; Ion irradiation; Iron compounds; Machines; Magnetic properties and materials; Magnetic properties of nanostructures; Manufacturing; Materials science; Methods of nanofabrication; Nanopowders; Nanoscale materials and structures: fabrication and characterization; Nanoscale pattern formation; Nanostructure; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Plasma focus; Platinum compounds; Processes; Shot; Surfaces and Interfaces; Thin Films; 75.75.+a; Radiation effects; Annealing; Phase transformations; Platinum alloys; Magnetic hysteresis; Experimental device; Pulsed laser deposition; Iron alloys; Ion beams; Thin films; Nanoparticles; Nanopatterning; Coercive force; Pulsed beam
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-009-5138-x

The effects of the different number (1, 2 and 3) of H + ion irradiation shots on pulsed laser deposited FePt thin films, using pulsed plasma focus device, are investigated. The FePt thin films were exposed to energetic H + ions in a plasma focus device at a fixed distance of 4 cm from the top of central electrode. It was deduced that single shot ion irradiation based transient thermal treatment induces an effect similar to the conventional annealing at 400°C. Well-separated nanoparticles are formed, and the significant enhancement of the coercivity, by about two orders of magnitude, at a lower annealing temperature of 400°C has been observed in the single shot ion irradiated samples. The increase of plasma focus ion irradiation shots lead to the amorphorization in irradiated FePt samples due to excessive energy transfer causing more defects and lattice distortion, and a decreasing coercivity trend in irradiated and annealed samples are observed due to reduction in the texture coefficient of magnetic easy axis (001) orientation fct phase.