Strain Gradient Elasticity in SrTiO 3 Membranes: Bending versus Stretching.

Autor:	Harbola V; Department of Physics, Stanford University, Stanford, California 94305, United States.; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States., Crossley S; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States.; Department of Applied Physics, Stanford University, Stanford, California 94305, United States., Hong SS; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States.; Department of Applied Physics, Stanford University, Stanford, California 94305, United States., Lu D; Department of Physics, Stanford University, Stanford, California 94305, United States.; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States., Birkhölzer YA; Department of Inorganic Materials Science, Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands., Hikita Y; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States., Hwang HY; Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States.; Department of Applied Physics, Stanford University, Stanford, California 94305, United States.
Jazyk:	angličtina
Zdroj:	Nano letters [Nano Lett] 2021 Mar 24; Vol. 21 (6), pp. 2470-2475. Date of Electronic Publication: 2021 Mar 10.
DOI:	10.1021/acs.nanolett.0c04787
Abstrakt:	Young's modulus determines the mechanical loads required to elastically stretch a material and also the loads required to bend it, given that bending stretches one surface while compressing the opposite one. Flexoelectric materials have the additional property of becoming electrically polarized when bent. The associated energy cost can additionally contribute to elasticity via strain gradients, particularly at small length scales where they are geometrically enhanced. Here, we present nanomechanical measurements of freely suspended SrTiO 3 crystalline membrane drumheads. We observe an unexpected nonmonotonic thickness dependence of Young's modulus upon small deflections. Furthermore, the modulus inferred from a predominantly bending deformation is three times larger than that of a predominantly stretching deformation for membranes thinner than 20 nm. In this regime we extract a strain gradient elastic coupling of ∼2.2 μN, which could be used in new operational regimes of nanoelectro-mechanics.
Databáze:	MEDLINE
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