Magnetic susceptibility of ferromagnetic metals: Application to nickel

Dynamic spin susceptibility of paramagnetic spinelLiV2O4

“…Therefore, this contribution is neglected below. After performing the integration in (21) we arrive at the following expression…”

“…28 To overcome this difficulty, an elegant procedure based on a simple and reliable approximation has been proposed and developed by several authors. 21,28 We are now in a position to discuss some preliminaries of this procedure, the central point of which is the search for a separable form for the plane-wave matrix elements entering Eq. (1).…”

“…In solving Eq. (17), we adopt a "diagonal" approximation 21 which consists in retaining in γ LL ′ only the diagonal composite indices,…”

Exchange interactions, spin waves, and transition temperatures in itinerant magnets

“…As is well known, the exact magnon dispersion law is obtained from poles of the dynamical transverse susceptibility while the effective exchange interactions are closely related to the static transverse susceptibility [32,33]. Susceptibility calculations within the DFT are, however, quite involved even for systems with perfect three-dimensional translational symmetry [152,52], which calls for additional approximations. The calculations can be simplified using again the adiabatic approximation and the ASA as done in reference [72].…”

Adiabatic spin dynamics from spin-density-functional theory: Application to Fe, Co, and Ni

“…The alternative approach [18][19][20][21][22] via the transverse dynamical susceptibility Ϫϩ (q,) does not rest on the adiabatic approximation and hence is able to describe both the magnon dispersion and the interband spin-flip continuum as well as their interference. On the other hand, the adiabatic approach yields the magnon stiffness with the same accuracy, but in addition yields all the details of far reaching exchange interactions, manifesting, e.g., in Kohn anomalies.…”