Abstract
Polarized neutron reflectometry (PNR) has been used to investigate the magnetic interlayer coupling in a MBE-grown Fe/Si/Fe(001) sandwich at room temperature and at 10 K. Both the magnitude and orientation of the magnetic moments of the Fe layers are obtained from a rigorous analysis of the PNR data. Orthogonal configurations of the Fe magnetizations were observed, providing unambiguous evidence for the presence of a biquadratic term in the exchange coupling energy. The competition between the bilinear and biquadratic exchange couplings results in distinct orthogonal and antiparallel configurations of the Fe magnetizations at room temperature. A previously unresolved magnetic configuration in the room-temperature hysteresis curve was identified by the PNR measurements as a 180° spin-flop transition. The dominant role of the biquadratic coupling at low temperatures is evident from the orthogonal configuration of the magnetizations at remanence in the measurements at T = 10 K. The magnetic configurations deduced by PNR are in good agreement with those obtained by fitting the magnetic hysteresis loops using a global energy minimum calculation.
| Original language | English |
|---|---|
| Article number | 064440 |
| Pages (from-to) | 644401-644407 |
| Number of pages | 7 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 65 |
| Issue number | 6 |
| Early online date | 24 Jan 2002 |
| DOIs | |
| Publication status | Published - 1 Feb 2002 |
| Externally published | Yes |
Keywords
- n/a OA procedure