Oxygen-vacancy-doping study of bulk KTaO3

ORAL

Abstract

Potassium tantalate (KTaO3, KTO) is an insulator and incipient ferroelectric with cubic perovskite structure [1]. Upon introducing charge carriers, KTO can become metallic and even superconducting [2]. The charge-carrier density in KTO is usually modified via oxygen-vacancy-doping, e.g., by controlling the oxygen atmosphere during crystal growth [3], irradiating with Ar+ ions [4], or depositing TiOx layers that act as an oxygen getter [5]. However, these methods either induce vacancies on the sample surface or are difficult to control. Here we report on an alternative, oxygen-getter-based annealing method. From transport and Hall measurement, we find that the charge-carrier density can be controlled with suitable annealing conditions and are able to obtain higher carrier concentrations (up to 8.1×1019 cm-3 to date) than previous works.

[1] C. Liu et al., Science 371, 716 (2021)

[2] K. Ueno et al., Nat. Tech. 6, 408 (2011)

[3] S. H. Wemple, Phys. Rev. 137, A1575 (1965)

[4] S. Harashima et al., Phys. Rev. B 88, 085102 (2013)

[5] A. H. Al-Tawhid et al., J. Electron. Mater. 51, 7073 (2022)

* Work supported by the US DOE through the University of Minnesota Center for Quantum Materials, under Grant No. DE-SC0016371.

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Presenters

  • Chiou Yang Tan

    University of Minnesota, Twin Cities, University of Minnesota

Authors

  • Chiou Yang Tan

    University of Minnesota, Twin Cities, University of Minnesota

  • Issam Khayr

    University of Minnesota, Twin Cities, University of Minnesota

  • Dinesh K Shukla

    UGC-DAE Consortium for Scientific Research, University of Minnesota, University of Minnesota, Twin Cities

  • Damjan Pelc

    University of Zagreb

  • Martin Greven

    University of Minnesota