Giant sharp and persistent converse magnetoelectric effects in multiferroic epitaxial heterostructures

Abstract

Magnetoelectric coupling^1,2 between magnetic and electrical properties presents valuable degrees of freedom for applications. The two most promising scenarios are magnetic-field sensors³ that could replace low-temperature superconducting quantum interference devices, and electric-write magnetic-read memory devices that combine the best² of ferroelectric and magnetic random-access memory. The former scenario requires magnetically induced continuous and reversible changes in electrical polarization. These are commonly observed, but the coupling constants thus obtained are invalid for data-storage applications, where the more difficult to achieve^4,5 and rarely studied magnetic response to an electric field is required. Here, we demonstrate electrically induced giant, sharp and persistent magnetic changes (up to 2.3×10⁻⁷ s m⁻¹) at a single epitaxial interface in ferromagnetic 40 nm La_0.67Sr_0.33MnO₃ films on 0.5 mm ferroelectric BaTiO₃ substrates. X-ray diffraction confirms strain coupling via ferroelastic non-180^∘ BaTiO₃ domains. Our findings are valid over a wide range of temperatures including room temperature, and should inspire further study with single epitaxial interfaces.