Infrared spectroscopy and nano-imaging of the insulator-to-metal transition in vanadium dioxide

Abstract

We present a detailed infrared study of the insulator-to-metal transition (IMT) in vanadium dioxide (VO2) thin films. Conventional infrared spectroscopy was employed to investigate the IMT in the far-field. Scanning near-field infrared microscopy directly revealed the percolative IMT with increasing temperature. We confirmed that the phase transition is also percolative with cooling across the IMT. We present extensive near-field infrared images of phase coexistence in the IMT regime in VO2. We find that the coexisting insulating and metallic regions at a fixed temperature are static on the time scale of our measurements. A novel approach for analyzing the far-field and near-field infrared data within the Bruggeman effective medium theory was employed to extract the optical constants of the incipient metallic puddles at the onset of the IMT. We found divergent effective carrier mass in the metallic puddles that demonstrates the importance of electronic correlations to the IMT in VO2. We employ the extended dipole model for a quantitative analysis of the observed near-field infrared amplitude contrast and compare the results with those obtained with the basic dipole model.

18 pages including 8 figures

References in corpus (8)

• Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging
• Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+d
• Interplay of electron-lattice interactions and superconductivity in Bi2Sr2CaCu2O8+d
• Electrodynamics of the vanadium oxides VO2 and V2O3
• Correlated metallic state of vanadium dioxide
• Role of electron-electron and electron-phonon interaction effect in the optical conductivity of VO2
• Electrostatic modification of infrared response in gated structures based on VO2
• Surface versus bulk characterization of the electronic inhomogeneity in a VO_{2} film

Cited by in corpus (18)

• Electrodynamics of Correlated Electron Materials
• Optical properties of correlated materials -- Generalized Peierls approach and its application to VO2
• Vacuum Thermal Switch Made of Phase Transition Materials Considering Thin Film and Substrate Effects
• Modulation and amplification of radiative far field heat transfer: Towards a simple radiative thermal transistor
• Wavelength-Tunable Infrared Metamaterial by Tailoring Magnetic Resonance Condition with VO2 Phase Transition
• Molecular Quantum Materials: Electronic Phases and Charge Dynamics in Two-Dimensional Organic Solids
• Programmable Mechanical Resonances in MEMS by Localized Joule Heating of Phase Change Materials
• Radiative Thermal Transistor
• Resistance noise at the metal-insulator transition in thermochromic VO2 films
• Influence of thermal boundary conditions on the current-driven resistive transition in $\mathbf{V}{\mathbf{O}}_2$ microbridges
• Non-contact Thermal Transistor Effects Modulated by Nanoscale Mechanical Deformation
• Multibridge VO2-Based Resistive Switching Devices in a Two-Terminal Configuration
• Decoherence and collective effects in critical media
• Artifact Free Transient Near-Field Nanoscopy
• Transport and spectroscopic signatures of a disorder-stabilized metal in two-dimensional frustrated Mott insulators
• Multi-probe detection of domain nucleation across the metal-insulator transition in VO${}_2$
• Optical forces on an oscillating dipole near VO${}_2$ phase transition
• Control of plasmonic nanoantennas by reversible metal-insulator transition