Self-Assembled Complex Three-Phase Core–Shell Nanostructure of Au–CoFe<sub>2</sub>–TiN with a Magneto-Optical Coupling Effect
Jiawei Song, Di Zhang, Ping Lu, Yizhi Zhang, Haohan Wang, Haohan Wang, Hongyi Dou, Xiaoshan Xu, Julia Deitz, X. Zhang, Haiyan Wang, Haiyan Wang
Abstract
Nanostructured plasmonic–magnetic metamaterials have gained great research interest due to their enhanced magneto-optical coupling effects. Here, we report a complex three-phase nanocomposite design combining ferromagnetic CoFe 2 with plasmonic TiN and Au as a multifunctional hybrid metamaterial using either a cogrowth or a templated method. Via the first method of cogrowing three phases, three different morphologies of Au–CoFe 2 core–shell nanopillars were formed in the TiN matrix. Via the second method of sequential deposition of a TiN–Au seed layer and a TiN–CoFe 2 layer, highly ordered and uniform single-type core–shell nanopillars (i.e., the CoFe 2 shell with a Au core) form in the TiN matrix. Both cogrowth and templated growth TiN–CoFe 2 –Au hybrid systems exhibit excellent epitaxial quality, hyperbolic dispersion, magnetic anisotropy, and a magneto-optical coupling effect. This study provides an effective approach for achieving highly uniform multiphase vertically aligned nanocomposite structures with well-integrated optical, magnetic, and coupling properties.