Magnetic spin valve

Figure 8.18 TbPc2-based molecular spin-tronic devices, (a) Graphene nanotransistor with sensitivity at the single-molecule level [39, 256], (b) Scheme of the supramolecular spin valve architecture [217]. (c) Scheme of the carbon nanotube NEMS. The magnetization reversal of a TbPc 2 SIMM from a spin state Jz = +6 to Jz = -6 results in a rotation...

The application of an external magnetic field will bend the orientation of the antiparallel magnetic domains toward the direction of the parallel domains. This situation creates a spin valve that is, charge carriers of the correct magnetic moment orientation may pass through the magnetic layers unscattered by their magnetic... 

Various experimental methods have been developed for investigating the magnetoelastic properties of thin films and nanoscale magnetic systems. In the following subsections, we discuss the most important ones (i) the magnetoelastic cantilever, (ii) strain induced anisotropy, (iii) magnetostriction in spin valves, (iv) strain modulated ferromagnetic resonance, (v) secondary-electron spin-polarisation, and (vi) strain-induced anisotropy due to the spontaneous strains. 

Figure 3. Magnetoresistance vs. magnetic field for a top-pinned spin valve coupon sample.

Mnlr based synthetic antiferromagnet spin valve [27]. These SAF structures have another advantage. Since the effective moment of the pinned layer is low (Meff = M - M2, where M is the moment of each ferromagnetic layer), its contribution to the demagnetizing and coupling fields acting on the free layer is much weaker than in conventional spin valves. Similar SAF structures can be used as synthetic free layers (SF), in order to reduce the effective magnetic thickness and moment of the free layer [28, 29],... 

When large current densities (10+7 A/cm2) cross CPP spin valves, spin transfer effects start to be observed. When a spin polarized DC current flows across the CPP device, both well defined spin wave modes, and chaotic spin wave generation has been observed as a function of the injected DC current [65], These spin-wave modes lead to excess magnetic noise. These effects were first predicted by Berger [66] and Slonczewski [67], and have been now experimentally observed by several groups. At low frequencies, spin transfer effects also affect the CPP device transfer curve [68], and can be used to induce free layer switching in magnetoresistive devices. 

---