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Flexible YIG-poly(vinyl-alcohol) magnetic composite films for microwave applications J. F. Barro´n-Lo´pez1,3,* H. Montiel3

, A. M. Boları´n-Miro´1

, F. Sa´nchez De-Jesu´s1

, V. Go´mez-Vidales2, and

1

Área Académica de Ciencias de la Tierra y Materiales, ICBI, Universidad Autónoma del Estado de Hidalgo, Pachuca-Tulancingo Km 4.5, Mineral de La Reforma, 42184 Hidalgo, Mexico 2 Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Cuidad Universitaria, Coyoacán, 04510 Mexico City, Mexico 3 Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Cuidad Universitaria, Coyoacán, 04510 Mexico City, Mexico

Received: 11 June 2020

ABSTRACT

Accepted: 10 September 2020

Flexible magnetic composite films based on yttrium iron garnet (YIG) and poly(vinyl alcohol) (PVA) with composition xYIG:(1 - x)PVA (0 B x B 0.63 wt) were successfully obtained by facile casting technique. The structure, magnetic, and microwave absorption properties of YIG/PVA films were characterized by XRD, Raman spectroscopy, FTIR, vibrant sample magnetometry (VSM), and ferromagnetic resonance (FMR) techniques. XRD, Raman and FTIR analysis confirmed the complete synthesis of YIG/PVA composites, without any chemical interaction between particles of YIG and PVA matrix. VSM experiments revealed a ferrimagnetic ordering in composite films with small in-plane anisotropy; their specific magnetization increases linearly with the YIG content. YIG/PVA films exhibit an effective imaginary microwave permeability of l00max * 0.1–0.5, as determined by FMR measurements. Numerical simulations of the FMR spectra showed that the large FMR linewidth of DH pp  80 kA/m is associated with the shape anisotropy and the interactions between YIG particles. A small effective field of H eff = 20–25 kA/m was originated by the confinement of YIG particles within a PVA matrix into a two-dimensional geometry. The combination of flexibility, magnetic, and microwave properties makes of YIG/ PVA films suitable materials for microwave absorption applications.

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Springer Science+Business

Media, LLC, part of Springer Nature 2020

Address correspondence to E-mail: [email protected]

https://doi.org/10.1007/s10854-020-04474-5

J Mater Sci: Mater Electron

Yttrium iron garnets (YIG: Y3Fe5O12) have attracted much attention as microwave device materials and as magneto-optical recording media, as well as for their unique magnetic and magneto-optical properties [1, 2]. YIG is a ferrimagnetic insulator which crystallizes in a bcc garnet type structure (space group No. 230, Ia3d), where magnetic Fe3? ions occupy octahedral and tetrahedral coordination sites, as schematically represented in Fig. 1a. YIG is widely known by having very small microwave losses [4, 5]; thus, it is applied in microwave resonators, Faraday rotators, filters, and circulators for radar and telecommunication applications [2]. YIG, being a

ceramic oxide, is also a hard and brittle material, which limits its application range when