Deterministic, Reversible, and Nonvolatile Low-Voltage Writing of Magnetic Domains in Epitaxial BaTiO₃/Fe₃O₄ Heterostructure

Abstract

The ability to electrically write magnetic bits is highly desirable for future magnetic memories and spintronic devices, though fully deterministic, reversible, and nonvolatile switching of magnetic moments by electric field remains elusive despite extensive research. In this work, we develop a concept to electrically switch magnetization via polarization modulated oxygen vacancies, and we demonstrate the idea in a multiferroic epitaxial heterostructure of BaTiO/FeO fabricated by pulsed laser deposition. The piezoelectricity and ferroelectricity of BaTiO have been confirmed by macro- and microscale measurements, for which FeO serves as the top electrode for switching the polarization. X-ray absorption spectroscopy and X-ray magnetic circular dichroism spectra indicate a mixture of Fe and Fe at O sites and Fe at T sites in FeO, while the room-temperature magnetic domains of FeO are revealed by microscopic magnetic force microscopy measurements. It is demonstrated that the magnetic domains of FeO can be switched by not only magnetic fields but also electric fields in a deterministic, reversible, and nonvolatile manner, wherein polarization reversal by electric field modulates the oxygen vacancy distribution in FeO, and thus its magnetic state, making it attractive for electrically written magnetic memories.

Self‐Polarized BaTiO3 for Greatly Enhanced Performance of ZnO UV Photodetector by Regulating the Distribution of Electron Concentration

“…Barium titanate (BaTiO 3 , BTO), a well‐known ferroelectric material having high dielectric constant, low dielectric loss, and promising ferroelectric properties, has been exploited in many applications such as gas sensing, waveguide modulators, pressure transducers, capacitors, and memory devices . In addition, BTO film can be prepared by a simple sol–gel spin‐coating method, which is compatible with the preparation of ZnO film.…”

Probing Ultrafast Dynamics of Ferroelectrics by Time‐Resolved Pump‐Probe Spectroscopy

“…As the polarization can be coupled with other intrinsic properties as well as external stimuli, the ferroelectric exhibits various physical properties, and is considered as a critical component in modern and future electronic elements. [ 14 , 15 , 16 , 17 , 18 , 19 ] As shown in Figure 1b , under the external stimuli of electric, stress, light, and magnetic fields, the ferroelectric enjoys multiple coupling effects of piezoelectric, [ 20 ] electric‐optic, [ 21 , 22 , 23 ] magneto‐electric, [ 24 , 25 ] piezo‐magnetic, [ 26 ] and magneto‐optic [ 27 ] effects, among others. [ 28 , 29 , 30 ] Based on these unusual physical properties, the ferroelectric materials have been employed for widespread applications such as pyroelectric sensors, piezoelectric actuators, electro‐optic modulators, and nonvolatile memories, [ 28 , 29 , 30 ] and other novel applications following the exploration of unusual polarization domain structures have also been conceived.…”

Vector imaging of electric field-induced reversible magnetization reversal in exchange-biased multiferroic heterostructures

“…E-field control of macroscopic properties, like H EB and magnetization values, has been extensively studied, but the magnetic domain evolution under E-fields in exchange-biased systems is still unclear. Relying on the vector imaging techniques, electrical regulation of magnetic domains has been achieved in many different forms [23][24][25][26], such as realizing various E-field responses of magnetic domains in CoFeB/PMN-PT (001) heterostructures attributed to different ferroelectric domain switching [27,28], less than 90°rotation of domains via E-fieldinduced shear strain effect [29,30], and reversible domain-wall motion based on the elastic coupling between magnetic and ferroelectric domain walls [31,32], etc. Meanwhile, E-fields can also be utilized to manipulate the domain wall velocity [33,34].…”