Interlayer exchange coupling was investigated in highly Co-enriched (75.6 at. ), i.e., in Co antisite defective Heusler alloy Co-Mn-Si-based epitaxial trilayer structures for a wide range of spacer Cr thicknesses (t Cr). The exchange coupling parameters J 1 (bilinear coupling) and J 2 (90 coupling) were estimated from the comparison of experimental and numerical simulations of M-H loops. The comparable contributions of both the bilinear and 90 couplings were observed in a spacer thickness range, t Cr ∼ 0.3 to 4.2 nm. The relative angle of magnetization at remanence between the bottom and top Co-Mn-Si layers was found to vary from 67 to a maximum of 152 as a result of competition between bilinear and 90 couplings. In contrast to the observation of strong 90 coupling without any detectable bilinear type 180 coupling in almost stoichiometric and chemically B2-ordered Co 2MnSi-based trilayer structures in a previous study, the results in this study clearly indicated the importance of the effect of chemical ordering on dominating 90 coupling in Heusler alloy-based structures.
ASJC Scopus subject areas
- Physics and Astronomy(all)