Annealing effects on the magnetoresistance characteristics of grain-type alloy thin films

Abstract

SmcNral, magnetoresistance (m), and magnetic chaacteristics were studied on FeCwAg grain-type alloy thin films annealed under various conditionr. Internal diffusion and interfacial diffusion of the Ag a" in the femmaguetic FeCo grains passessed negative and positive contributions to obtaining a large MR ratio, respectively. The magnetic anisotropy field ( H i ) associated wilh the MU characteristics decreased in accordance with the decrease in resistivity as the annealing tempemme and/or annealing time inneased. This suggests that the Ruderman-Kiltel-Kasuya-yosida interaction between the ferroma&netic grains dominates the Hk in such systems.When two kinds of metal that are mutually insoluble are evaporated or sputtered at the same time, each metal is known to individually form fine grains in the prepared film [I]. Recently, it has been observed that a giant magnetoresistance ( G m ) effect is present in such 'grain-type alloy thin films' comprising magnetic and non-magnetic metals l2-71. These results demonstrated that the G m effect is not restricted to multilayered structures and they showed that additional oppoitunities exist for technological applications. However, the magnetic anisotropy field (H,) associated with the m characteristics, which is important in the application of MR head devices, was too large in such grain systems. From our studies

A study of the electrodeposition of Co–Cu alloys thin films on FTO substrate

“…Furthermore, these patterns display an fcc and hcp phase, with peaks quite close to those of the Co phase (fcc and hcp). No peaks of the Cu fcc phase were found, which we suggest is due to the Cu clusters being too small to produce reflections [28] and only produce a distortion of the Co lattice. It is interesting to note that such a distinct phase separation was not observed in the X-ray diffractogram studied by most of the previous researchers [13,16,25] under DC deposition of Cu-Co alloys from an electrolyte without additive agent, except studies by Cohen-Hyams et al [14].…”

Magneto-Transport Properties of Co–Cu Thin Films Obtained by Co-Sputtering and Sputter Gas Aggregation

“…No reflections of Co (either fcc or hcp) are found, not even after annealing (which usually favors the segregation of the Co from the Cu matrix). This is likely due to the small size of the Co clusters, giving rise to a distortion of the Cu matrix [ 27 ] or very small peaks (overlapping with those of the Cu matrix). In the as-deposited samples, the position of the peak is displaced with reference to the position of pure Cu fcc (indicated by a vertical line in the picture).…”