Aging-Induced Strong Anomalous Hall Effect at Room Temperature for Cu(Co) Nanoparticle Film

The Co 0.12 Cu 0.88 nanoparticle film with two-dimensional hexagonally arranged microsized pores is fabricated by electrochemical deposition. Subsequent aging at room temperature leads to change of the film in carrier type from n-type to p-type and appearance of anomalous Hall effect. The anomalous Hall effect is well controlled by aging time at room temperature and increases to a maximum (the Hall slope > 40 mΩ cm/T in the field below 40 Oe) with further aging almost 80 times as high as the best value reported previously. Such results are attributed to the formation of the alloy/oxide core−shell nanoparticles during aging. This study could help in the design and fabrication of transparent spintronic devices operable at room temperature.