Structural Aftershocks in VO2 Switching

Image Caption: 
The device is probed by an X-ray diffractometer with ~200nm spatial and ~1ns time resolution to explore the current-triggered phase transition in VO2
Credits/Names: 

G. Stone2, M. Jerry2, H. Wen1, Z. Cai1, H. Paik3, R. Engel-­‐Herbery2, D. Schlom3, S. DaCa2, V. Gopalan2 at 1 Argonne; 2 Penn State; 3,Cornell NSF DMR-­‐0820404

A current passed through VO2 destabilizes the monoclinic semiconducting phase and induces a phase transition to the tetragonal metallic phase. While the electronic transition to the low resistance state is very fast, a complex and unexpected spatially varying structural distortion pattern is detected, lagging behind the electronic transition. These “structural aftershocks” reveal a complex interplay of electronic and structural phase transitions in VO2 on ultrashort time scales in a device configuration which is of high relevance for newly proposed low power logic devices, such as hyper-FETs (10.1038/ncomms8812) or VO2 oscillator based non-Boolean computing (10.1038/srep04964)

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Year of Research Highlight: 
2015
IRG: 
IRG 4 - Multicomponent Assemblies for Collective Function