R&D: Localized Strain Profile in Surface Electrode Array for Programmable Composite Multiferroic Devices

Applied Physics Letters has published an article written by Zhuyun Xiao, Chelsea Lai, Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, USA, Ruoda Zheng, Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095, USA, Maite Goiriena-Goikoetxea, Department of Electrical Engineering and Computer Science, University of California, Berkeley, California 94720, USA, and Department of Electricity and Electronics, University of the Basque Country, Leioa 48940, Spain, Nobumichi Tamura, Advanced Light Source, Lawrence Berkeley National Lab, Berkeley, California 94720, USA, Cornelio Torres Juarez, Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095, USA, Colin Perry, Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, USA, Hanuman Singh, Jeffrey Bokor, Department of Electrical Engineering and Computer Science, University of California, Berkeley, California 94720, USA, Gregory P. Carman, Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095, USA, and Rob N. Candler, Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, USA, Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, California 90095, USA, and California NanoSystems Institute, Los Angeles, California 90095, USA.

Abstract: “We investigate localized in-plane strains on the microscale, induced by arrays of biased surface electrodes patterned on piezoelectrics. Particular focus is given to the influence that adjacent electrode pairs have on one another to study the impact of densely packed electrode arrays. We present a series of X-ray microdiffraction studies to reveal the spatially resolved micrometer-scale strain distribution. The strain maps with micrometer-scale resolution highlight how the local strain profile in square regions up to 250 × 250 μm² in size is affected by the surface electrodes that are patterned on ferroelectric single-crystal [Pb(Mg_1/3Nb_2/3)O₃]_x-[PbTiO₃]_1−x. The experimental measurements and simulation results show the influence of electrode pair distance, positioning of the electrode pair, including the angle of placement, and neighboring electrode pair arrangements on the strength and direction of the regional strain. Our findings are relevant to the development of microarchitected strain-mediated multiferroic devices. The electrode arrays could provide array-addressable localized strain control for applications including straintronic memory, probabilistic computing platforms, microwave devices, and magnetic-activated cell sorting platforms.“

We gratefully acknowledge the support from the NSF Nanosystems Engineering Research Center for Translational Applications of Nanoscale Multiferroic Systems (TANMS) under the Cooperative Agreement Award No. EEC-1160504. We also acknowledge the use of the cleanroom service for device fabrication in the UCLA Nanolab at the University of California, Los Angeles. X-ray microdiffraction at the Advanced Light Source and fabrication at the Molecular Foundry were supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02–05CH11231. M.G.-G. acknowledges the support of the Basque Government for the Postdoctoral Fellowship. The authors are very grateful to Jizhai Cui, Roberto Lo Conte, Camelia Stan, and Jinzhao Hu for their valuable discussions and to Arian Gashi for his support on fabrication at the Molecular Foundry. C.L., C.T.J., and C.P. acknowledge the support of the TANMS Undergraduate Research Program.