Strain-gradient-induced magnetic anisotropy in straight-stripe mixed-phase bismuth ferrites: Insight into flexomagnetism

Abstract

Implementation of antiferromagnetic compounds as active elements in spintronics has been hindered by their insensitive nature against external perturbations which causes difficulties in switching among different antiferromagnetic spin configurations. Electrically-controllable strain gradient can become a key parameter to tune the antiferromagnetic states of multiferroic materials. We have discovered a correlation between an electrically-written straight-stripe mixed-phase boundary and an in-plane antiferromagnetic spin axis in highly-

Phenomenology of chiral Dzyaloshinskii-Moriya interactions in strained materials

“…Finally, we provide examples of two relevant strain fields which can lead to cDM interactions in intrinsically DM-inactive materials. Our analysis expands upon previous reports of strain and geometry-coupled magnetic phenomena [18][19][20][21][22][23][24], and provides a general roadmap for controlling chiral magnetic interactions via strain in materials of all symmetries.…”

Magnetically induced electromechanical fields in a flexoelectric composite microplate

“…Another similar coupling phenomenon-namely, flexomagnetic effect-can be realized through a coupling of the magnetization and strain gradients [13]. Recently, some insightful studies and experiments about flexomagnetic effect were given in Eliseev et al [14] and Lee et al [15]. Different from piezoelectricity, the flexoelectric effect is a weak effect of little practical significance on the application of macrostructures.…”

Strain‐Gradient‐Induced Unidirectional Magnetic Anisotropy in Nanocrystalline Thin Permalloy Films

“…In another study of mixed-phase perovskite, La-5%-doped BiFeO3, it was found that in those regions of the sample where electric-field-induced elongated stripes of the mixed-phase boundary were formed, the antiferromagnetic axis was oriented perpendicular to the elongation axis. [24] Theoretical analysis showed that this magnetic behavior could be explained by the magnetic anisotropy induced near the phase boundaries by a shift of Fe ions with respect to the oxygen cage caused by strain gradients. However, there is still no direct convincing proof of the existence of the flexomagnetic effect, and there are also no direct experimental measurements of its magnitude.…”

“…There have been only few studies on the subject published to date. [19][20][21][22][23][24] Lukashev and Sabirianov [19] performed first-principles calculations of the flexomagnetic coefficient for the antiperovskite Mn3GaN, which was about 0.2 µB nm. Eliseev et al [20,21] theoretically showed that in the case of infinite medium the flexomagnetic effect could exist in 69 of 90 magnetic classes, while in samples of finite size near the surface it can exist for any magnetic class.…”