title: Counting vacancies and nitrogen-vacancy centers in detonation nanodiamond.
abstract: Detonation nanodiamond particles (DND) contain highly-stable nitrogen-vacancy (N-V) centers, making it important for quantum-optical and biotechnology applications. However, due to the small particle size, the N-V concentrations are believed to be intrinsically very low, spawning efforts to understand the formation of N-V centers and vacancies, and increase their concentration. Here we show that vacancies in DND can be detected and quantified using simulation-aided electron energy loss spectroscopy. Despite the small particle size, we find that vacancies exist at concentrations of about 1 at%. Based on this experimental finding, we use ab initio calculations to predict that about one fifth of vacancies in DND form N-V centers. The ability to directly detect and quantify vacancies in DND, and predict the corresponding N-V formation probability, has a significant impact to those emerging technologies where higher concentrations and better dispersion of N-V centres are critically required.
authors.affiliation: Leroy Eyring Center for Solid State Science, Arizona State University, Tempe, USA. shery.chang@asu.edu.
authors.forename: Shery L Y
authors.initials: SL
authors.lastname: Chang
authors.affiliation: Virtual Nanoscience Laboratory, CSIRO, Parkville, Australia.
authors.forename: Amanda S
authors.initials: AS
authors.lastname: Barnard
authors.affiliation: Department of Physics, Arizona State University, Tempe, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Dwyer
authors.affiliation: Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich, Germany.
authors.forename: Chris B
authors.initials: CB
authors.lastname: Boothroyd
authors.affiliation: College of Science Technology and Engineering, James Cook University, Townsville, Australia.
authors.forename: Rosalie K
authors.initials: RK
authors.lastname: Hocking
authors.affiliation: NanoCarbon Research Institute, Ueda, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Ōsawa
authors.affiliation: Department of Materials, University of Oxford, UK. rebecca.nicholls@materials.ox.ac.uk.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Nicholls