Correlation between crystal purity and the charge density wave in 1<i>T</i>-VSe<sub>2</sub>

POSTER

Abstract

We discuss the charge density wave (CDW) properties of 1T-VSe2 crystals grown by chemical vapour transport (CVT) under varying conditions [1]. We find that by lowering the growth temperature (Tg < 630°C), there is a significant increase in both the CDW transition temperature and the residual resistance ratio (RRR) obtained from electrical transport measurements. Using x-ray photoelectron spectroscopy (XPS), we correlate the observed CDW properties with stoichiometry and the nature of defects. In addition, we have optimized a method to grow ultra-high purity 1T-VSe2 crystals with TCDW = (112.7 ± 0.8) K and maximum RRR value ∼ 49. Our work highlights the importance of carefully controlling the crystal growth conditions of strongly-correlated transition metal dichalcogenides.

[1] C. J. Sayers et al. Phys. Rev. Materials 4, 025002 (2020)

*The authors acknowledge funding from the EPSRC CDT-CMP Grant No. EP/L015544/1, and the Bristol NanoESCA facility EPSRC Grant Nos. EP/K035746/1 and EP/M000605/1. We thank the Elettra synchrotron for access to the BEAR beamline (Proposal No. 20180358).

Presenters

  • Charles Sayers

    • University of Bath
    • Politecnico di Milano

Authors

  • Charles Sayers

    • University of Bath
    • Politecnico di Milano

  • Liam Farrar

    • University of Bath

  • Simon J Bending

    • University of Bath

  • Mattia Cattelan

    • University of Bristol

  • Alfred Jones

    • University of Bristol

  • Neil Fox

    • University of Bristol

  • Gabriele Kociok-Köhn

    • University of Bath
    • Material and Chemical Characterization Facility, University of Bath

  • Konstantin Koshmak

    • IOM-CNR Institute, Elettra Sincrotrone Trieste

  • Jude Laverock

    • University of Bristol
    • H. H. Wills Physics Laboratory, University of Bristol

  • Luca Pasquali

    • Università di Modena e Reggio Emilia
    • University of Modena & Reggio Emilia

  • Enrico Da Como

    • University of Bath