Muon states in metals: Recent progress
- University of Jyväskylä
We report on our results in two interesting questions related to muon spin rotation studies in condensed matter: (i) energetics of muons in metals, including lattice relaxation and zero point motion in self-trapping phenomena, and (ii) systematics of Knight shifts and hyperfine fields. In the former topic, a comprehensive theory is developed which entails the construction of the muon potential energy field in terms of the "effective-medium" or "quasi-atom" theory first introduced by Zaremba, Stott, NØrskov and Lang. The muon wave function is then solved by numerical (3-D) relaxation techniques. From this the forces exerted by the muon on the neighbouring lattice atoms are calculated, and the ensuing relaxations are evaluated by lattice Green's function techniques. These in turn modify the potential energy field, and the calculation is iterated to self-consistency. We search for the stable trapping sites in bcc and fcc metals, calculate self-trapping energies, diffusion barriers and excitation energies. Other hydrogenic imputies are also considered, and isotopic effects in e.g. heats of solution are investigated. In the latter topic, the spin-density functional theory is applied, including in the Knight shift calculation both the contact spin density and the diamagnetic shielding. The lattice potential is described in terms of the spherical solid model. A systematic behaviour as a function of the electron density and the host valency is found in good agreement with the experimental results.
|Tila||Julkaistu - tammikuuta 1984|
|OKM-julkaisutyyppi||A1 Julkaistu artikkeli, soviteltu|