Strain Engineering of Magnetic Anisotropy in Epitaxial Films of Cobalt Ferrite (Adv. Mater. Interfaces 23/2021)

Abstract

Strain Engineering of Magnetic Anisotropy In article number 2101034, Hiroshige Onoda, Hideto Yanagihara, and co‐workers demonstrate that the strain engineering technique is a promising way to induce large magnetic anisotropy without using heavy metals or rare earth elements. The spins (red arrows) of Co ions (light blue) on the octahedral sublattice of the spinel structure change their preferred direction in response to the epitaxial stress of the cobalt ferrite thin film due to the change in the orbital moment.

Magnetoelastic constant of thin films determined by a four-point bending apparatus

“…A phenomenon of MA induced by strain is called the magnetoelastic effect or the inverse magnetostriction effect. [12][13][14][15][16][17][18][19] Epitaxial strain originating from the lattice mismatch between thin films and single-crystal substrates is the most widely used way to introduce large lattice strain. However, due to the limited choice of substrate/thin film combinations, this technique cannot achieve fine control of strain in the thin film over a wide range.…”

“…However, due to the limited choice of substrate/thin film combinations, this technique cannot achieve fine control of strain in the thin film over a wide range. 18) There are only a few reports that quantitatively evaluate the continuous change in the magnetic properties with respect to various lattice strains because of the difficulties encountered by continuously varying lattice distortions. One way to introduce adjustable lattice distortion into a film is to apply the four-point bending (4PB) technique.…”