Tunable Metallic Conductance in Ferroelectric Nanodomains

• Published in: Nano letters 2012-01, Vol.12 (1), p.209-213
• Main Authors: Maksymovych, Peter, Morozovska, Anna N, Yu, Pu, Eliseev, Eugene A, Chu, Ying-Hao, Ramesh, Ramamoorthy, Baddorf, Arthur P, Kalinin, Sergei V
• Format: Article
• Language: English
• Subjects: Carrier density; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Conductance; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Domain walls; Electric Conductivity; Electric fields; Electromagnetic Fields; Electron states; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Ferroelectric materials; Ferroelectricity; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Macromolecular Substances - chemistry; Macromolecular Substances - radiation effects; Materials Testing; Metal-insulator transitions and other electronic transitions; Metals - chemistry; Metals - radiation effects; Molecular Conformation - radiation effects; Nanostructure; Nanostructures - chemistry; Nanostructures - radiation effects; Nanostructures - ultrastructure; Physics; Polarization; Surface Properties - radiation effects; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Titanates
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl203349b

Metallic conductance in charged ferroelectric domain walls was predicted more than 40 years ago as the first example of an electronically active homointerface in a nonconductive material. Despite decades of research on oxide interfaces and ferroic systems, the metal–insulator transition induced solely by polarization charges without any additional chemical modification has consistently eluded the experimental realm. Here we show that a localized insulator–metal transition can be repeatedly induced within an insulating ferroelectric lead-zirconate titanate, merely by switching its polarization at the nanoscale. This surprising effect is traced to tilted boundaries of ferroelectric nanodomains, that act as localized homointerfaces within the perovskite lattice, with inherently tunable carrier density. Metallic conductance is unique to nanodomains, while the conductivity of extended domain walls and domain surfaces is thermally activated. Foreseeing future applications, we demonstrate that a continuum of nonvolatile metallic states across decades of conductance can be encoded in the size of ferroelectric nanodomains using electric field.