Multiferroic materials present a model system for examining and manipulating the coupling between the electric and magnetic orders. Electrically controlled magnetic order can also lead to novel devices utilized in the information technology with higher speed, higher density and lower power consumption. In this project, I propose a novel strategy to control different ferroic orders in epitaxial complex oxide heterostructures, exploring charge and strain engineered interface magnetoelectric coupling. The material system consists of a magnetic host material embedded with an array of ferroelectric nanopillars. I plan to fabricate the complex oxide nanostructures using advanced physical vapor deposition techniques, employ nanolithography and scanning probe approach, and carry out magnetotransport and magnetometry measurements on the proposed structures.
The objectives of this study include:
1. Control the magnetic phase using the ferroelectric field effect and conventional electric field effect;
2. Investigate how the magnetoelectric coupling is affected by interface atomic re-arrangement, electric field effect induced charge carrier density modulation, and piezoelectric effect induced strain modulation;
3. Examine the geometry related effects, such as the finite size effect and critical coupling length, to optimize the system design for maximized magnetoelectric coupling.
The success of this project can enrich our fundamental understanding of magnetoelectric coupling at the nanoscale, facilitate the rational design of novel multifunctional materials, and potentially lead to new oxide-based devices such as electric field-controlled spintronic devices.
