Magnetoelectric Coupling in Membrane Thin-film Heterostructures
Author | : Shane Lindemann |
Publisher | : |
Total Pages | : 0 |
Release | : 2022 |
ISBN-10 | : OCLC:1381367798 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Magnetoelectric Coupling in Membrane Thin-film Heterostructures written by Shane Lindemann and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strain-coupling in ferromagnetic (FM) / ferroelectric (FE) multiferroic heterostructures shows promise to become the next generation of low-power, ultra-fast memory storage devices in addition to opening new avenues of fundamental scientific research. The relaxor ferroelectric (1-x)Pb(Mg1/3Nb2/3)O3-(x)PbTiO3 (PMN-PT) is an ideal candidate as the FE layer due to its giant piezoelectricity. By coupling with a FM overlayer, an applied bias across the PMN-PT results in the generation of large piezostrains which are transferred into the FM layer to alter the FM's magnetic anisotropy, resulting in a piezo-driven magnetoelectric (ME) effect. This has been demonstrated using bulk single crystals of PMN-PT coupled with FM overlayers, but the bulk dimensions required application of over 100V applied bias. For low power coupling to be achieved, thin films of PMN-PT must be used.Strain-mediated ME coupling in thin film heterostructures has proven to be difficult due to two major challenges: 1) Elastic clamping by the substrate acts to eliminate giant piezoelectricity in PMN-PT thin films. 2) The films must exhibit anisotropic in-plane strain to alter in-plane magnetic anisotropy of a FM overlayer. Our approach to overcome these challenges is through growth of epitaxial thin films of PMN-PT followed by release of the films from their substrate to make ME membranes. After release from the substrate, we observe a recovery of giant piezoelectricity in PMN-PT membranes and demonstrate successful ME coupling with Ni overlayers. We found that for (001) oriented PMN-PT membranes, the nominally isotropic in-plane strains are transformed into anisotropic in-plane strains through Piezotensor Engineering, i.e. an interaction between biased and unbiased regions dictated by the electrode geometry. In (011) PMN-PT membranes, intrinsic anisotropic in-plane strains result in a 90-degree rotation of Ni's in-plane anisotropy with only 3V bias across the PMN-PT, demonstrating that PMN-PT membranes can achieve low power ME coupling. The membrane assembled heterostructures will lead to novel strain-mediated devices through heterogeneous integration. Individual membranes of various materials, including complex oxides, III-V's, and 2-Dimensional (2D) materials, can be stacked together with the PMN-PT membranes providing an exciting pathway to study an extraordinary range of piezo-driven phenomena and functionalities.