MAGNETOTRANSPORT PROPERTIES OF FE0.8GA0.2 FILMS WITH STRIPE DOMAINS

M. GRANADA; S. BUSTINGORRY; D. PONTELLO; M. BARTUREN; M. EDDRIEF; M. MARANGOLO; J. MILANO

Glasgow

Simposio; 8th Joint European Magnetic Symposia; 2016

Fe1−xGax alloys have been widely studied in the last decade due to their relatively high magnetostriction coefficient, roughly 10 times larger than iron, at moderate magnetic fields. Moreover, interesting applications in devices based on Fe1−xGax films have been proposed, like microwave filters or magnetic field sensors. In recent years, Fe1−xGax magnetostrictive alloys have been studied in thin film form, deposited by different techniques. In particular, magnetic domains with stripe geometry were observed in films fabricated by molecular beam epitaxy (MBE).In this work, magnetotransport properties of Fe0.8Ga0.2 films grown by MBE with stripe domains are studied. The anisotropic magnetoresistance dominates the low field behavior, which is extremely dependent on the magnetic domains configuration. The magnetoresistance measured at different temperatures displays qualitatively different behaviors depending on the measurement configuration. When the stripes are perpendicular to the electric current the magnetoresistance curves are nearly temperature-independent [Fig. (a)], while when the stripes are oriented along the electric current, the low-field magnetoresistance changes sign with temperature [Fig. (b)].A simple model considering parallel (series) conduction along (across) the stripes, plus the temperature dependence of anisotropic magnetoresistance and domains configuration, accounts for these experimental results.