Giant Piezo-Driven Multiferroic Heterstructures by Design
Abstract
Strain coupling between piezoelectric and ferromagnetic layers in multiferroic thin films and heterostructures is a fascinating opportunity for both fundamental scientific research and potential multifunctional device applications. Specifically, hyper-active heterostructures with giant piezoelectricity have sufficiently large responses to revolutionize low power piezo-driven magnetoelectric devices. We have demonstrated giant piezoelectricity in Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) epitaxial thin film heterostructures on silicon (S.H. Baek et al., Science, 334, 958 (2011)) as well as in free-standing membranes. The giant piezo-response and novel structural and piezoelectric characteristics make this an excellent material platform to realize low power multifunctional devices. We now have the capability to engineer the material and design its interfaces with other active materials to produce magnetoelectrically coupled device structures. We assemble a team with the respective expertise to model, design, fabricate, characterize, and evaluate device structures. We propose to not only make advances in magnetoelectric devices, but also to understand the fundamental mechanisms of magnetoelectric coupling and multiscale characteristics that control the properties and device performances. The thrusts of our proposed work are: (1) Theoretical/Computational modeling: Phase-field simulations in combination with microelasticity theory, electrostatics, and micromagnetics to understand and optimize the giant-piezoresponses of membranes and the magnetoelectric coupling of piezo-driven multiferroic heterostructures, (2) Fabrication of giant piezo-driven magnetoelectric heterostructures: Fabrication of epitaxial giant piezo/magnetic heterostructures on clamping substrates, and as free standing membranes, for enhanced magnetoelectric coupling at low voltage, (3) Magnetic and magneto-optic and magneto transport: Magneto-Optic Kerr Effect (MOKE) and anisotropic magneto resistance (AMR) to study the piezo-driven changes in local magnetization and global magnetoresistance. These combined multiscale characterization techniques of both the magnetic domains and the magnetic properties, along with our unique phase-field modeling technique, allows us to fundamentally understand the piezo-driven magnetoelectric coupling at different length scales. (4) Structures for low-power magnetoelectric devices: Low power/low voltage magnetoelectric devices with novel functionality, including switching magnetism and manipulation of ground states to discover new phenomena and develop multifunctional devices The proposed research will open new routes for the design of magnetoelectric interactions and device geometries to optimize low power magnetoelectric devices. The key to this proposed research is the use of strain coupling between the giant piezoelectric thin film membranes and the ferromagnetic layer, not mediated by the interface sensitive exchange coupling. Such an approach would provide the basis for a deterministic and scalable device design and discovery of new physical phenomena.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 18, 2018
- Source ID
- W911NF1710462
Entities
People
- Chang-Beom Eom
Organizations
- Army Contracting Command
- United States Army
- University of Wisconsin–Madison