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arXiv · 2505.19370

Structural, magnetic, and nanoacoustic characterization of Co/Pt superlattices

E. R. Cardozo de Oliveira·C. Xiang·C. Borrazás·S. Sandeep·J. E. Gómez·M. Vásquez Mansilla·N. Findling·L. Largeau·N. D. Lanzillotti-Kimura·M. Granada
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Abstract

Superlattices presenting a spatial modulation of the elastic properties appear as a main tool to reach the THz regime in nanoacoustic devices. The exploration of alternative materials with multifunctional properties remains a fertile domain of research. In this work, we study the structural, magnetic, and acoustic characteristics of nanometric superlattices made of Pt/Co. The samples present a well defined periodicity, as determined by X-ray reflectometry, whereas scanning transmission electron microscopy with local compositional analysis reveals that the superlattices present a modulation in composition instead of sharp interfaces. The policrystalline nature of the superlattices is evidenced both by X ray diffraction and transmission electron microscopy. Magnetization measurements show a perpendicular magnetic anisotropy for the higher Co concentrations. Picosecond acoustic experiments evidence that the studied samples support short-lived acoustic modes up to 900 GHz, and up to 7 acoustic echoes at lower frequencies.These are promising results for the development of magnetoacoustic devices working at ultrahigh frequencies.

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E. R. Cardozo de Oliveira, C. Xiang, C. Borrazás, S. Sandeep, J. E. Gómez, M. Vásquez Mansilla, N. Findling, L. Largeau, N. D. Lanzillotti-Kimura, M. Granada. 2025-05-25. Structural, magnetic, and nanoacoustic characterization of Co/Pt superlattices. https://arxiv.org/abs/2505.19370

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