BaTiO3 nanoparticle-decorated hierarchical Ni nanowire assemblies for magnetoelectric applications

Abstract

One dimensional multiferroic systems with spin-charge coupling at room temperature are highly useful in future multifunctional devices. A facile protocol was used to process one dimensional multiferroic heterostructures of Ni–BaTiO₃ (Ni@BTO) by adopting the wet chemical reduction of hierarchical Ni nanowires, followed by controlled addition of barium titanate nanoparticles. The magnetic and electric properties of hierarchical Ni nanowires decorated with BaTiO₃ (BTO) nanoparticles suggest that their magnetic and electric transport mechanisms are influenced by ferroelectric BaTiO₃ coating. The surface between the prickles in the hierarchical Ni nanowires is visibly covered with BTO nanoparticles, forming a partial core–shell magnetoelectric system. In the typical Ni@BTO, improved coercivity was achieved and the magnetoelectric coupling coefficient of 517 μV cm⁻¹ Oe⁻¹ was obtained. Since ferromagnetic metals are conducting, Ni-based multiferroic composite structures were difficult to realize. Nevertheless, this is the first report on the encapsulation of nickel-based nanowires with barium titanate, where the former is synthesized without the aid of templates, external magnetic field, or pressure. Hence, the suggested protocol has the potential to develop leakage-free, tailor-made magnetoelectric nanostructures for memory applications.