Magnetic Properties of Nano-Structured Ferromagnetic Dot Arrays

✍ Scribed by Otani, Y. ;Shima, H. ;Guslienko, K. ;Novosad, V. ;Fukamichi, K.

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 130 KB
• Volume: 189
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/1521-396x(200202)189:2<521::aid-pssa521>3.0.co;2-#

✦ Synopsis

The magnetization reversal processes in Fe-Ni disk arrays have been studied both experimentally and theoretically. The disks with variable thickness from 40 to 80 nm, inter-disk spacings from 100 to 800 nm, and diameters from 200 to 800 nm were fabricated by using electron beam lithography and lift-off technique. A size dependent vortex nucleation, annihilation fields, and initial susceptibility were determined from magneto-optical hysteresis loops. Disk diameters and inter-disk spacings are found to be important for determining the initial susceptibility, nucleation, and annihilation fields. Both nucleation and annihilation fields decrease with increasing the diameter or decreasing the interdisk spacing, whereas the initial susceptibility exhibits a linear increase with the diameter. The experimental data were compared to the results of analytical calculations taking into account magnetostatic interactions, exchange and Zeeman energies for an array of magnetically soft circular disks.