Session J16: Vanadium Dioxide; Nano and Devices

11:15 AM–2:15 PM, Tuesday, February 28, 2012
Room: 251

Sponsoring Unit: DCMP
Chair: Ivan Schuller, University of California, San Diego

Abstract ID: BAPS.2012.MAR.J16.13

Abstract: J16.00013 : Field-effect modulation of conductance in VO$_2$ nanobeam transistors with HfO$_2$ as the gate dielectric

1:39 PM–1:51 PM

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Authors:

  Shamashis Sengupta
    (Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai)

  Kevin Wang
    (Department of Materials Science and Engineering, University of California, Berkeley)

  Kai Liu
    (Department of Materials Science and Engineering, University of California, Berkeley)

  Ajay Bhat
    (Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai)

  Sajal Dhara
    (Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai)

  Junqiao Wu
    (Department of Materials Science and Engineering, University of California, Berkeley)

  Mandar M. Deshmukh
    (Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai)

Field-effect transistors have been fabricated from VO$_2$ nanobeams using HfO$_2$ as the gate dielectric. When heated up from low to high temperatures, VO$_2$ undergoes an insulator-to-metal transition. We observe a change in conductance (6 \%) of our devices induced by gate voltage when the system is in the insulating phase. The response is reversible and hysteretic, and the area of the hysteresis loop becomes larger as the rate of gate sweep is slowed down. A phase lag exists between the response of the conductance and the gate voltage. This indicates the existence of a memory of the system involving a timescale of a few minutes. The origin of such slow processes may lie in the coupling between the dipolar arrangement and the strain state of the VO$_2$ crystal.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.MAR.J16.13