Inverse giant magnetoresistance inFe∕Cu∕Gd1−xCoxspin-valves

Enhanced exchange and reduced magnetization of Gd in an Fe/Gd/Fe trilayer

“…Before the Fe completes its switching, the free FeCo layer switches, and the DSV reaches the maximum resistance at point (2). Only at slightly higher positive fields does the Fe layer complete its switching, and the resistance drops slightly to the plateau at point (3). The Fe and the free FeCo layers are again slightly coupled due to the roughness introduced by the Fe (orange-peel coupling).…”

“…The saturation magnetization of the Fe layer remains roughly constant from 10 K to room temperature for M S (Fe) = 1545 emu/cm 3 (the value for our samples; see magnetization for Gd of M S (Gd) = 1030 emu/cm 3 . This value is considerably smaller than the bulk saturation magnetization for Gd, 2056 emu/cm 3 , but it is similar to the reduced magnetization in thin-film Gd reported by other authors.…”

“…Also, we show that the magnetization of Gd in thin films is substantially reduced from the bulk value. The magnetization we measure in thin films is 1030 emu/cm 3 , while the bulk value is almost double, 2056 emu/cm 3 . A 20-30% reduction of the magnetization of Gd in Gd/Fe multilayers has previously been reported by several groups, [13][14][15] but very rarely is the reduction as large as the one reported here.…”

“…2 The alloys of RE and TM can also lead to negative mangetoresistance (MR) in a structure, as the alignment of its magnetic moment with the external magnetic field will depend on the proportion of RE and TM. Typical examples for this are the Gd 1−x Co x and Gd 1−x (CoFe) x alloys, [3][4][5] whose magnetic moment and spin polarization can be adjusted with the composition. 6 Other recent applications of REs and their alloys are the reduction of spin-transfer noise in reading heads, 7 tuning the resonance of a magnetic domain wall, 8 and the nucleation and characterization of an in-plane magnetic domain wall.…”

Inverted magnetoresistance in dual spin valve structures with a synthetic antiferromagnetic free layer

“…Recently, several experimental and theoretical studies have shown an inverted GMR effect in different systems. [4][5][6][7][8][9] In the rare-earth transition metal multilayers, inverted GMR is due to the direct AF coupling across a Co/Dy interface. 4 Due to the increase of the density of states at the Fermi level for majority spin electrons in the Fe 1−x V x / Au/ Co system 5 and doping effect in the Co/Ru/ CoRu system, 6 the spin polarization of the conduction band having opposite sign in alternate FM layers results in inverted GMR.…”