Room Temperature Magnetic Rare-Earth Iron Garnet Thin Films with Ordered Mesoporous Structure

• Tipo: Artigo em Revista Científica Internacional
• Data: 2013

Autores

suchomski, christian (Autor) Outra; reitz, christian (Autor) Outra; sousa, celia t. (Autor) Outra; araujo, joao p. (Autor) FCUP; brezesinski, torsten (Autor) Outra

Revista

Título: Chemistry of Materials

Vol. 25

Páginas: 2527-2537

ISSN: 0897-4756

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 36 Citações

Scopus - 38 Citações

Outras Informações

ID Authenticus: P-006-A00

DOI: 10.1021/cm400999b

Abstract (EN): Amphiphilic polymers are very attractive as porogens for the preparation of ordered mesoporous thin films and powders with pore sizes ranging from 40 down to a few nanometers in diameter because they are capable of both forming different superstructures and interacting with sol-gel precursors. In the present work, we report for the first time the synthesis of a series of highly crystalline rare-earth iron garnet (RE3Fe5O12, RE = Y, Gd-Dy) thin films with cubic networks of interconnected pores averaging 17 nm in diameter through facile polymer templating of hydrated nitrate salts. Despite intricate crystallization pathways, e.g., Y3Fe5O12 via Y4Fe2O9 and h-YFeO3, the nanoscale architecture of all these materials is only affected to a limited extent by solid-solid conversions at elevated temperatures. We specifically focus on the characterization of the morphology, microstructure, and magnetic properties of polymer-templated Y3Fe5O12. This novel mesoporous material is single phase after heating to 900 degrees C, free of major structural defects, and is also well-defined on the atomic level, as evidenced by a combination of in situ and ex situ scattering/diffraction techniques, electron microscopy, Raman and X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. The high quality of the nanocrystalline Y3Fe5O12 thin films with overall soft magnetic properties and moderate anisotropy is further confirmed by SQUID magnetometry measurements. The magnetization behavior in the temperature range 5-380 K describes Bloch's T-3/2 law for a 3D Heisenberg-type ferromagnet well.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11