Giant Electric Field Tuning of Magnetic Properties in Multiferroic Ferrite/Ferroelectric Heterostructures

TLDR

The study proposes that combining external magnetic orientation with electric field can significantly enhance microwave tunability up to 1000 Oe. Fe₃O₄ ferrite films were spin‑sprayed onto PZT, PMN‑PT, and PZN‑PT substrates at 90 °C to form multiferroic heterostructures. Strong magnetoelectric coupling yields giant microwave tunability, with FMR field shifts up to 860 Oe (ME coefficient 108 Oe cm kV⁻¹) and a 40 % change in squareness ratio, indicating promising electrostatically tunable microwave devices.

Abstract

Abstract Multiferroic heterostructures of Fe 3 O 4 /PZT (lead zirconium titanate), Fe 3 O 4 /PMN‐PT (lead magnesium niobate‐lead titanate) and Fe 3 O 4 /PZN‐PT (lead zinc niobate‐lead titanate) are prepared by spin‐spray depositing Fe 3 O 4 ferrite film on ferroelectric PZT, PMN‐PT and PZN‐PT substrates at a low temperature of 90 °C. Strong magnetoelectric coupling (ME) and giant microwave tunability are demonstrated by a electrostatic field induced magnetic anisotropic field change in these heterostructures. A high electrostatically tunable ferromagnetic resonance (FMR) field shift up to 600 Oe, corresponding to a large microwave ME coefficient of 67 Oe cm kV −1 , is observed in Fe 3 O 4 /PMN‐PT heterostructures. A record‐high electrostatically tunable FMR field range of 860 Oe with a linewidth of 330–380 Oe is demonstrated in Fe 3 O 4 /PZN‐PT heterostructure, corresponding to a ME coefficient of 108 Oe cm kV −1 . Static ME interaction is also investigated and a maximum electric field induced squareness ratio change of 40% is observed in Fe 3 O 4 /PZN‐PT. In addition, a new concept that the external magnetic orientation and the electric field cooperate to determine microwave magnetic tunability is brought forth to significantly enhance the microwave tunable range up to 1000 Oe. These low temperature synthesized multiferroic heterostructures exhibiting giant electrostatically induced tunable magnetic resonance field at microwave frequencies provide great opportunities for electrostatically tunable microwave multiferroic devices.