Effect of High Zn Concentration on the Structural, Electrical, and Magnetic Properties of Zn-Doped Yttrium Iron...

Current-induced magnetoelectric (ME) effect offers the potential for broadband, low-power tunable microwave devices. While yttrium iron garnet (YIG) is the most used ferrite due to its superior magnetic properties, its high-quality dielectric properties hinder its potential tuning with an electric current. To increase YIG's conductivity, we investigated Zn²⁺-doped YIG nanoparticles and nanocomposites (Y₃Fe_5-2x ³⁺Fe _x ⁴⁺Zn _x O₁₂) synthesized using the sol-gel method within a broad concentration range of dopants (0 < x < 1.0). Herein, for the first time, we report the effect of high-level Zn doping on the electrical conductivity and ferromagnetic resonance (FMR) of a YIG nanocomposite material. An increase in Zn concentration resulted in the formation of the yttrium iron perovskite (YIP) phase, and for concentrations above 0.6, the sol-gel synthesis yielded the predominant formation of YIP. Y₃Fe_4.7Zn_0.3O₁₂ had the highest Zn content when the garnet phase was predominantly formed during the synthesis. The increase in the Zn content in the lattice enhanced the conductivity of yttrium iron garnet doped with Zn (YIG:Zn) by up to 3 orders of magnitude compared to that of pure YIG. In addition, the increase in the Zn content yielded an increase in the domain and ferromagnetic resonance frequencies of the YIG:Zn material. Overall, highly doped YIG:Zn nanocomposites have the potential to enable current-induced ME due to their superior conductivity.