Elektronen-Spektroskopie zur Untersuchung der Statik und Dynamik der magnetischen Austauschwechselwirkung
Elektronen-Spektroskopie zur Untersuchung der Statik und Dynamik der magnetischen Austauschwechselwirkung
This thesis deals with two fundamental questions concerning magnetic data storage. The first question addressed, is: Does a magnetic exchange coupling exist between ferromagnetic layers separated by a semiconducting interlayer. Using SPLEED and MLD in photoemission, a ferromagnetic coupling between...
| Personal Name(s): | Scholl, A. (Corresponding author) |
|---|---|
| Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
| Imprint: |
Jülich
Forschungszentrum Jülich, Zentralbibliothek, Verlag
1998
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| Physical Description: |
111 p. |
| Document Type: |
Report Book |
| Research Program: |
ohne Topic |
| Series Title: |
Berichte des Forschungszentrums Jülich
3582 |
| Link: |
OpenAccess OpenAccess |
| Publikationsportal JuSER |
|
This thesis deals with two fundamental questions concerning magnetic data storage. The first question addressed, is: Does a magnetic exchange coupling exist between ferromagnetic layers separated by a semiconducting interlayer. Using SPLEED and MLD in photoemission, a ferromagnetic coupling between Fe layers separated by a ZnSe layer has been observed. The coupling strength decreases exponentially with increasing interlayer thickness, in agreement with theoretical predictions. Uncoupled, thin Fe layers on ZnSe below 10 $\mathring{A}$ thickness do not show an in plane magnetic signal which is explained as an anisotropic effect. This has been utilized as a very sensitive means to measure the coupling to the buried Fe layer in Fe/ZnSe/Fe. The second part of this thesis deals with the magnetic response of a ferromagnetic material on an ultrafast optical excitation with f-sec laser pulses. Two magnetic relaxation channels have been observed, one on a sub p-sec time scale, and the other on a time scale of several hundred p-sec. The fast relaxation is attributed to the creation of Stoner excitations and a decrease of the local magnetic moment, the slow one to magnon-phonon coupling and a reduction of the long range magnetic order. |