Phonon-magnon scattering

Phonon-magnon scattering, heat transfer by magnons in lanthanide compounds (r[Pg.107]

If heat transfer is to occur by magnons or phonon-magnon scattering it is... 

By contrast, in EuO the effect of phonon -magnon scattering is small and the heat at low temperatures is transferred mainly be magnons. At T = 0.93 K the contribution of c , to K in EuO is about 75%, fig. 22. This value is a record for the investigated magnetics at the present time. However, simple dependences like those shown in figs. 21 and 22 (Dixon and Landau 1976, Walton et al. 1973, Metcalfe and Rosenberg... 

Phonon and magnon scattering 2.3.3. Effects of the material s optical 515 4.3.3. Evidence for nrxmal-state pairing 5. Electronic scattering in the superconducting 541... 

Inelastic scattering of radiation in solids is typified by the Raman effect, which involves the creation or annihilation of phonons or magnons. If a single phonon is involved, the scattering event is referred to as the first-order Raman effect in second-order Raman effect two phonons are involved. The polarizability associated with a phonon mode can be represented as a power series of the phonon amplitude, u, as follows ... 

A spin polaron should move at low temperatures with a fixed wave vector k, like any other pseudoparticle, and be scattered by phonons and magnons. The effective mass is expected to be of the form mey /0, where y l. To obtain this result, we compute the transfer integral when the polaron moves through one atomic distance. The spin will contribute a term proportional to... 

The use of lasers for the excitation of Raman spectra of solids has led to the detection of many new elementary excitations of crystals and to the observation of nonlinear effects. In this review we have tried to lead the reader to a basic understanding of these elementary excitations or quasi-particles, namely, phonons, polaritons, plasmons, plasmaritons, Landau levels, and magnons. Particular emphasis was placed upon linear and stimulated Raman scattering at polaritons, because the authors are most familiar with this part of the field and because it facilitates understanding of the other quasi-particles. 

Abstract Electronic correlation effects in La2.ISrINi04 lead to spontaneous phase separation into microscopic spin/charge stripes with commensurate or incommensurate order. Raman scattering experiments on such single crystalline materials show a rich phenomenology of phonon and magnon anomalies due to the new, self-organized periodicities. These effects are observable as function of temperature. 

Key words Raman scattering, stripe ordering, phonon and two-magnon excitations... 

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