Probing magnetoelastic effects of ultrathin antiferromagnets via magnetic domain imaging in ferromagnetic-antiferromagnetic bilayers

Abstract

We report an experimental investigation of the magnetoelastic effects of ultrathin antiferromagnets, performed by comparing the characteristic behavior of the induced spin-reorientation transition (SRT) of Co films in two types of epitaxially grown bilayers: face-centered-cubic (fcc)-like Mn/Co (fcc-Mn: a = 3.75Å, c = 3.76Å) and face-centered-tetragonal (fct)-Mn (a = 3.61Å, c = 3.78Å). Magnetic hysteresis loops and magnetic domain images indicate that both fcc-Mn and fct-Mn films can produce a 110 to 100 SRT in adjacent Co films when the thickness of the Mn layer is greater than a temperature-dependent critical value. Detailed analysis of the critical thickness of Mn films and the evolution of the Co domain structure upon SRT indicate that the fct-Mn film had a higher antiferromagnetic ordering temperature and stronger lateral Mn-Mn exchange coupling compared with the fcc-Mn film. The enhanced long-range antiferromagnetic ordering emerging concurrently with the in-plane lattice variation of the fcc-like Mn film in Mn/Co bilayers clearly showed the magnetoelastic effect of ultrathin antiferromagnets.

General nature of the step-induced frustration at ferromagnetic/antiferromagnetic interfaces: topological origin and quantitative understanding

“…In an independent study, Yamada et al repeated the same measurement on a system with Mn on top of Fe(001), but found the domain-wall width to be nearly independent of the Mn thickness [19]. Similar frustrated spin configurations have also been reported in other systems [8,9,[20][21][22][23][24][25][26][27][28][29][30]. The frustration induced domain wall in nanorings is considered to lead to potential logic and memory applications [31].…”

Promoting control of antiferromagnet-induced perpendicular magnetic anisotropy in magnetic multilayers: Effects of applying in-plane magnetic supporting layers

“…Current approaches to circumvent such issues involve strategies such as alloying or engineering the crystalline structure to increase the T Ordering of AFM films. 13,16,17) An alternative approach to promote the thermal stability of long-range AFM ordering in AFM ultrathin films involves applying magnetic proximity effects, which describe an increase in the T Ordering of one magnetic film from another higher-T Ordering magnetic layer through direct exchange coupling. [18][19][20] By applying such an effect, a study showed that the PMA of Fe/Mn bilayers is enhanced after the incorporation of a perpendicular magnetic ultrathin Fe supporting layer.…”