Anisotropic three-dimensional weak localization in ultrananocrystalline diamond films with nitrogen inclusions

L. H. Willems van Beveren, D. L. Creedon, N. Eikenberg, K. Ganesan, B. C. Johnson, G. Chimowa, D. Churochkin, S. Bhattacharyya, and S. Prawer

Phys. Rev. B 101, 115306 – Published 23 March 2020

Abstract

We present a study of the structural and electronic properties of ultrananocrystalline diamond films that were modified by adding nitrogen to the gas mixture during chemical vapor deposition growth. Hall bar devices were fabricated from the resulting films to investigate their electrical conduction as a function of both temperature and magnetic field. Through low-temperature magnetoresistance measurements, we present strong evidence that the dominant conduction mechanism in these films can be explained by a combination of three-dimensional weak localization (3DWL) and thermally activated hopping at higher temperatures. An anisotropic 3DWL model is then applied to extract the phase-coherence time as a function of temperature, which shows evidence of a power-law dependence in good agreement with theory.

3 More

Received 22 August 2019
Accepted 10 March 2020

DOI:https://doi.org/10.1103/PhysRevB.101.115306

Physics Subject Headings (PhySH)

Anisotropic magnetoresistance Electrical conductivity Grain boundaries Hopping transport Weak localization

Hall bar Scanning electron microscopy

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

L. H. Willems van Beveren ^1,*, D. L. Creedon ¹, N. Eikenberg¹, K. Ganesan¹, B. C. Johnson¹, G. Chimowa^2,†, D. Churochkin^2,‡, S. Bhattacharyya^2,§, and S. Prawer¹

¹School of Physics, University of Melbourne, Parkville, VIC 3010, Australia
²Nano-Scale Transport Physics Laboratory, School of Physics, University of the Witwatersrand, Johannesburg 2050, South Africa

^*Author to whom all correspondence should be addressed: laurensw@unimelb.edu.au
^†Botswana International University of Science and Technology, P. Bag 16, Palapye, Botswana.
^‡Saratov State University, Saratov 410012, Russia.
^§National University of Science and Technology MISIS, Moscow 119049, Leninsky pr. 4, Russia.

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 101, Iss. 11 — 15 March 2020

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Physical Review B

covering condensed matter and materials physics