Giant magnetoresistance; a primer
1992; Linguagem: Inglês
10.1109/intmag.1992.696345
Autores Tópico(s)Theoretical and Computational Physics
ResumoIn 1988, Babich et al reported that the application of a magnetic field to multilayer ultrathin films in the (Fe/Cr)n family produced very large changes in the electrical resistance of the film, changes in Δρ/ρ approaching 100% at low temperatures. This is to be contrasted with the Δρ/ρ values on the order of 1% arising from normal bulk magneto-resistance. The Fe films in the multilayer structure had been previously established to be exchange coupled antiferromagnetically through the Cr layer (in itself a very interesting phenomenon); application of sufficient magnetic field overwhelmed the exchange interaction and rendered the magnetization of all Fe layers parallel. The large change of resistance accompanied the change of magnetic structure from successive layers magnetized antiparallel to parallel. This discovery triggered an avalanche of studies on transition metal/non-magnetic metal multilayers, and it was found that giant magnetoresistance was a widely occurring, but not universal, phenomenon. Values of Δρ/ρ as large as 65% at room temperature (in Co/Cu multilayers) have been reported.
Referência(s)