title: Self-Assembled, Nanostructured, Tunable Metamaterials via Spinodal Decomposition.
abstract: Self-assembly via nanoscale phase separation offers an elegant route to fabricate nanocomposites with physical properties unattainable in single-component systems. One important class of nanocomposites are optical metamaterials which exhibit exotic properties and lead to opportunities for agile control of light propagation. Such metamaterials are typically fabricated via expensive and hard-to-scale top-down processes requiring precise integration of dissimilar materials. In turn, there is a need for alternative, more efficient routes to fabricate large-scale metamaterials for practical applications with deep-subwavelength resolution. Here, we demonstrate a bottom-up approach to fabricate scalable nanostructured metamaterials via spinodal decomposition. To demonstrate the potential of such an approach, we leverage the innate spinodal decomposition of the VO2-TiO2system, the metal-to-insulator transition in VO2, and thin-film epitaxy, to produce self-organized nanostructures with coherent interfaces and a structural unit cell down to 15 nm (tunable between horizontally and vertically aligned lamellae) wherein the iso-frequency surface is temperature-tunable from elliptic to hyperbolic dispersion producing metamaterial behavior. These results provide an efficient route for the fabrication of nanostructured metamaterials and other nanocomposites for desired functionalities.
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.|Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Zuhuang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.affiliation: Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials, Key Laboratory of Green Preparation and Application for Materials, Ministry of Education, Department of Materials Science and Engineering, Hubei University , Wuhan 430062, P.R. China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|NSF Nanoscale Science and Engineering Center (NSEC), University of California, Berkeley , Berkeley, California 94720, United States.
authors.forename: Sui
authors.initials: S
authors.lastname: Yang
authors.affiliation: Materials Research Laboratory, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
authors.forename: Julio A N T
authors.initials: JA
authors.lastname: Soares
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Apgar
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Ran
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Ruijuan
authors.initials: R
authors.lastname: Xu
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Yeonbae
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|NSF Nanoscale Science and Engineering Center (NSEC), University of California, Berkeley , Berkeley, California 94720, United States.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.|Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Yao
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.|Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Lane W
authors.initials: LW
authors.lastname: Martin
keywords: VO2; epitaxial thin films; metamaterials; nanoscale phase separation; self-assembly; spinodal decomposition