Anisotropy effects on the magnetic excitations of a ferromagnetic monolayer below and above the Curie temperature
| dc.creator | Pini, M. G. | |
| dc.creator | Politi, P. | |
| dc.creator | Stamps, R. L. | |
| dc.date | 2005-03-22 | |
| dc.date | 2005-07-22 | |
| dc.date.accessioned | 2026-07-07T03:04:16Z | |
| dc.date.available | 2026-07-07T03:04:16Z | |
| dc.description | The field-driven reorientation transition of an anisotropic ferromagnetic monolayer is studied within the context of a finite-temperature Green's function theory. The equilibrium state and the field dependence of the magnon energy gap $E_0$ are calculated for static magnetic field $H$ applied in plane along an easy or a hard axis. In the latter case, the in-plane reorientation of the magnetization is shown to be continuous at T=0, in agreement with free spin wave theory, and discontinuous at finite temperature $T>0$, in contrast with the prediction of mean field theory. The discontinuity in the orientation angle creates a jump in the magnon energy gap, and it is the reason why, for $T>0$, the energy does not go to zero at the reorientation field. Above the Curie temperature $T_C$, the magnon energy gap $E_0(H)$ vanishes for H=0 both in the easy and in the hard case. As $H$ is increased, the gap is found to increase almost linearly with $H$, but with different slopes depending on the field orientation. In particular, the slope is smaller when $H$ is along the hard axis. Such a magnetic anisotropy of the spin-wave energies is shown to persist well above $T_C$ ($T \approx 1.2 T_C$). | |
| dc.description | Final version accepted for publication in Physical Review B (with three figures) | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0503538 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0503538 | |
| dc.identifier | Phys. Rev. B 72, 014454 (2005) (11 journal pages) | |
| dc.identifier | doi:10.1103/PhysRevB.72.014454 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/26071 | |
| dc.subject | Materials Science | |
| dc.title | Anisotropy effects on the magnetic excitations of a ferromagnetic monolayer below and above the Curie temperature | |
| dc.type | text |