Temperature-dependent exchange splitting of the magnetic Gd(0 0 0 1) surface state
Abstract
The temperature-dependent energy difference of both spin counterparts of the d z2-like surface state of Gd(0 0 0 1) films being held responsible for the surface magnetic properties was investigated by means of variable-temperature scanning tunneling spectroscopy. This exchange splitting amounts to 700 meV at 20 K and decreases down to 400 meV at 300 K. Above 300 K the splitting remains constant. Pure spin-mixing as well as pure Stoner-like behavior can therefore be excluded. A theoretical description explains the observation by a local spin-polarization due to the atomic 4f moments which compete with spin-mixing caused by the thermal fluctuations of these moments. The results suggest that the high spatial localization of the surface states helps to maintain a local exchange splitting even above the Curie temperature but does not cause an enhanced surface Curie temperature.
- Publication:
-
Journal of Magnetism and Magnetic Materials
- Pub Date:
- April 1998
- DOI:
- 10.1016/S0304-8853(97)01140-2
- Bibcode:
- 1998JMMM..184..155G