Disordered local moment

Figure 7.3. Planar spin spiral energetics for bcc Fe, fee Co, and fee Ni directly calculated from the BGFM (filled symbols) and evaluated using the magnetic force theorem with ferromagnetic (FM-MFT, dashed lines) and disordered local moment reference states (DLM-MFT, continuous lines). Energies are measured relative to the NM energy, and the moment is fixed to the ground state moment.

In addition to substitutional randomness, the DMSs are characterized also by some degree of magnetic disorder" which we treat in terms of the disordered local moment (DLM) method" that can be naturally incorporated in the CPA the Mn atoms have collinear, but random spin-up (Mn ) and spin-down (Mn ) orientations. It is worthwhile to mention that for total energy calculations it is not necessary to consider all possible 25-1-1 projections of the atomic spin it is sufficient to carry out the calculations for only two extremal values, namely 5 . The corresponding concentrations x and a fnlfill the condition x = +x. The degree of magnetic disorder... 

Mossbauer spectroscopy is also able to give local moment orientations, with respect to the crystalline lattice, or the correlations between moment orientations and local distortion axis orientations in a chemically disordered or amorphous material. This arises from the interplay between the structural (electric field gradient) hyperfine parameters and the magnetic hyperfine parameters. In this way, the spin flop Morin transition of hematite, for example, is easily detected and characterized (e.g., Dang et al. 1998). The noncollinear magnetic structures of nanoparticles can also be characterized. 

When an external force (e.g. an electric field or a temperature gradient) is applied to a conductor, all the electrons are displaced in Ar-space. Random scattering effects tend to restore the electrons to the steady-state distribution. The nature of this distribution is determined by a dynamical balance between the acceleration in the field and the scattering by deviations of perfect symmetry in the lattice (lattice distortion, phonons, disordered local magnetic moments). 

---