Magnetic order in semiconducting, ferromagnetic Ga1-xMnxAs
Author
Summary, in English
Magnetic resonance studies allow us to distinguish paramagnetic, ferromagnetic and ferrimagnetic phases in Ga1-xMnxAs. The transition from ferromagnet to ferrimagnet is correlated with a metal to insulator transition. The analysis of spin wave resonance spectra, which occur in the ferrimagnetic phase, allows us to estimate the magnitude and the distance dependence of exchange coupling. The experimentally evaluated long range of exchange causes an effective averaging of the fluctuation of exchange interactions. As a consequence, in the semimetallic phase both spin subsystems coherently precess forming the ferrimagnetic structure. In the insulating phase, fluctuations of the local exchange field lead to a fast decoherence of the carrier spins and only the localized Mn spins form the ferromagnetic moment.
Department/s
Publishing year
2004
Language
English
Pages
492-493
Publication/Series
Semiconductor Science and Technology
Volume
19
Issue
4
Document type
Journal article
Publisher
IOP Publishing
Topic
- Physical Sciences
- Natural Sciences
Status
Published
ISBN/ISSN/Other
- ISSN: 0268-1242