Twinned-domain-induced magnonic modes in epitaxial LSMO/STO films

Erik Wahlström,Roland Mathieu,Åsmund Monsen,Ferran Macià,Per Nordblad,Jos E Boschker,Jos E Boschker,Thomas Tybell,Andrew D Kent

doi:10.1088/1367-2630/aa70af

Abstract

The use of periodic magnetic structures to control the magneto-dynamic properties of materials—magnonics—is a rapidly developing field. In the last decade, a number of studies have shown that metallic films can be patterned or combined in patterns that give rise to well-defined magnetization modes, which are formed due to band folding or band gap effects. To explore and utilize these effects in a wide frequency range, it is necessary to pattern samples at the sub-micrometer scale. However, it is still a major challenge to produce low-loss magnonic structures with periodicities at such length scales. Here, we show that for a prototypical perovskite, MnO3, the twinned structural order can be used to induce a magnetic modulation with a period smaller than 100 nm, demonstrating a bottom-up approach for magnonic crystal growth.

Highlights

- Thermodynamic conditions during growth determine the magnetic anisotropy in epitaxial thin-films of La0.7Sr0.3MnO3 J M Vila-Fungueiriño, Cong Tinh Bui, B Rivas-Murias et al
We show that twinned structural order in a perovskite with a composition of La0.7Sr0.3 MnO3/ SrTiO3(001) (LSMO/STO) induced by crystal growth produces a modulation of the film magnetization with a period that is smaller than 100 nm, effectively creating a magnonic crystal
A periodic strain could cause a periodic variation of the Curie temperature, TC, of the LSMO film [14,15,16,17], creating a modulation of the internal effective field caused by the different saturation magnetization values and eventually introducing additional modes to the ferromagnetic resonance (FMR)

Summary

Introduction

- Thermodynamic conditions during growth determine the magnetic anisotropy in epitaxial thin-films of La0.7Sr0.3MnO3 J M Vila-Fungueiriño, Cong Tinh Bui, B Rivas-Murias et al. Such structures are denominated magnonic crystals and allow dynamic modes with different resonance frequencies to be established as well as the formation of frequency band gaps, offering the opportunity to build novel magnetic thin-film devices with well controllable properties [5].

Results

Conclusion