The magnetic properties of multiply Mn δ-doped GaAs samples with various spacer widths are investigated to precisely evaluate the interlayer ferromagnetic interaction. Curie temperature as well as coercive field and remanent magnetization decrease when spacer width increases, owing to suppression of the ferromagnetic coupling between δ-doped (Ga,Mn)As planes. In particular, coercive field and remanent magnetization disappear when the spacer width exceeds 7 monolayers since the ferromagnetic interaction between Mn-doped layers is completely suppressed and thus, each layer independently acts as a ferromagnet. In contrast, saturation magnetization increases and becomes constant for wider spacers probably because of the suppression of the formation of interstitial Mn, which compensates for holes and forms antiferromagnetic coupling with substitutional Ga.
ASJC Scopus subject areas
- Physics and Astronomy(all)