Local modifications of magnetism and structure in FePt (001) epitaxial thin films by focused ion beam: Two-dimensional perpendicular patterns

Journal Article · Mon Sep 01 00:00:00 EDT 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2975217· OSTI ID:21182603

Albertini, F; Nasi, L; Casoli, F; Fabbrici, S ^[1]; Luches, P; Gazzadi, G C; Di Bona, A ^[2]; Vavassori, P ^[2]; Valeri, S; Contri, S F ^[3]

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1. IMEM-CNR, Parco Area delle Scienze 37/A, I-43010 Parma (Italy)
2. S3 CNR-INFM, via G. Campi 213/a, I-41100 Modena (Italy)
3. S3 CNR-INFM, via G. Campi 213/a, I-41100 Modena (Italy) and Dipartimento di Fisica, Universita di Modena, via G. Campi 213/a, I-41100 Modena (Italy)

Focused ion beam was utilized to locally modify magnetism and structure of L1{sub 0} FePt perpendicular thin films. As a first step, we have performed a magnetic, morphological, and structural study of completely irradiated FePt films with different Ga{sup +} doses (1x10{sup 13} -4x10{sup 16} ions/cm{sup 2}) and ion beam energy of 30 keV. For doses of 1x10{sup 14} ions/cm{sup 2} and above a complete transition from the ordered L1{sub 0} to the disordered A1 phase was found to occur, resulting in a drop of magnetic anisotropy and in the consequent moment reorientation from out-of-plane to in-plane. The lowest effective dose in disordering the structure (1x10{sup 14} ions/cm{sup 2}) was found not to affect the film morphology. Taking advantage of these results, continuous two-dimensional (2D) patterns of perpendicular magnetic structures (250 nm dots, 1 {mu}m dots, 1 {mu}m-large stripes) were produced by focused ion beam without affecting the morphology. The 2D patterns were revealed by means of magnetic force microscopy, that evidenced peculiar domain structures in the case of 1 {mu}m dots.

• OSTI ID: 21182603
• Journal Information: Journal of Applied Physics, Vol. 104, Issue 5; Other Information: DOI: 10.1063/1.2975217; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ATOMIC FORCE MICROSCOPY
BINARY ALLOY SYSTEMS
DOMAIN STRUCTURE
EPITAXY
GALLIUM IONS
ION BEAMS
IRON ALLOYS
KEV RANGE 10-100
MAGNETIC FIELDS
MAGNETIC MOMENTS
MAGNETISM
MORPHOLOGY
ORDER-DISORDER TRANSFORMATIONS
PLATINUM ALLOYS
THIN FILMS