Magnetic structure of Laves type superlattices
Abstract
We present a determination of the magnetic structures of two superlattices of the form [6 ∼nm DyFe2 / 6 nm ErFe_2] and [8 nm DyFe2 / 4 ∼nm ErFe_2], both prepared by molecular beam epitaxy on a sapphire (11\overline20) substrate. The layers crystallize in the fcc Laves phase structure with the surface normal being along [110]. The experiments were carried out using neutron diffraction on the triple-axis spectrometer C5 at the NRU reactor in Chalk River. We measured in zero field and in a horizontal field of 2.6 ∼T applied along [001], which is the easy axis for bulk DyFe_2, along [111], which is the easy axis of bulk ErFe_2, and along the surface normal [110]. The temperature was varied in the range from 4 ∼K to 250 ∼K. The data analysis shows that the direction of the magnetization is a delicate balance between the Zeeman energy favoring the field direction, the crystalline anisotropies favoring either the [001] or [111] direction, and the exchange interaction at the interface favoring a parallel orientation of the magnetizations of both layers. Surprisingly we find that the moments rotate out of the plane on cooling even when constrained by an in-plane field along [001].
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARN23007F