29 January 2019:
CNBP PhD student, Marco Capelli (RMIT) has recently undertaken a three month residency at the Fraunhofer IAF (Institute for Applied Solid State Physics) in Freiburg, Germany. He reports on his work and collaborative activity there, focused on furthering the measurement of magnetic fields with diamond crystals.
During the months from October to December I worked with the group of Diamond Magnetometry at the Fraunhofer IAF (Institute for Applied Solid State Physics) in Freiburg, Germany.
The group leader Dr. Jan Jeske already collaborated with the CNBP in the past. His group is developing a new technique, building a laser from the fluorescence of diamond and using the enhanced signal to develop a more compact and less expensive diamond device able to perform magnetoencephalography (MEG) with high resolution and sensitivity.
At the Fraunhofer IAF I worked on our common goal of pushing further the ability of measuring magnetic fields with diamond crystals. It was a full collaborative work that put together my knowledge about magnetometry, helping optimising their existing setups and experimental procedures, with their ability to grow diamond samples with specific and tailored characteristics, searching for the best diamond to use.
I was able to compare the sample I previously used in my studies with their diamond samples and study how they differ and which are the best suited for magnetometry. This comparison is still at the beginning and our groups will further collaborate in the near future to get a full understanding of the diamond material.
The work helped me learn and better understand how diamonds can be created, how much they can be ‘customised’ and which parameters to keep in mind when choosing the appropriate diamond to use in my experiments. The students and researchers I met were keen to share their expertise and show me their advanced facilities to grow diamond. In addition it was a great learning experience to work at the institute itself. As the institute is more focused with practical applications and connecting with industry, it was personally interesting to see the differing kinds of management and organisational structures in place there.
Below: Marco (third left) with the Diamond Magnetometry team.
24 November 2018:
An improved method to convert nitrogen to nitrogen-vacancy (NV) color centers in diamond has been reported by CNBP researchers in a paper published in the journal Carbon. Lead author of the paper was CNBP student Marco Capelli (pictured).
Publication title: Increased nitrogen-vacancy centre creation yield in diamond through electron beam irradiation at high temperature.
Authors: M. Capelli, A.H. Heffernan, T. Ohshima, H. Abe, J. Jeske, A. Hope, A.D. Greentree, P. Reineck, B.C. Gibson.
Abstract: The nitrogen-vacancy (NV) centre is a fluorescent defect in diamond that is of critical importance for applications from ensemble sensing to biolabelling. Hence, understanding and optimising the creation of NV centres in diamond is vital for technological progress in these areas. We demonstrate that simultaneous
electron irradiation and annealing of a high-pressure high-temperature diamond sample increases the NV centre creation efficiency from substitutional nitrogen defects by up to 117 % with respect to a sample where the processes are carried out consecutively, but using the same process parameters. This increase in fluorescence is supported by visible and infrared absorption spectroscopy experiments. Our results pave the way for a more efficient creation of NV centres in diamond as well as higher overall NV densities in the future.
20 June 2018:
Approximately 100 patrons at the Belgian Beer Cafe in Melbourne were treated to ten researchers showcasing their science as part of the ‘Fresh Science’ initiative (Victoria), June 20th, 2018.
One of those ten researchers was CNBP student Marco Capelli from RMIT University who was a successful applicant to Fresh Science – a program that trains early career scientists on how to best communicate and present their activity to the media and to the wider general public at large.
Studying the brain using ulta-small diamonds was the scientific narrative practiced and delivered by Marco as part of his public presentation at the Cafe.
“Fresh Science was an amazing experience,” says Marco.
“Over the course of two days, I had the chance to interact with journalists from different media (including television, radio and newspaper) as well as representatives from industry and policymakers. From each of them, I learned how to tailor my scientific exposition to a variety of audiences, how to highlight my research and how to successfully pitch my ideas.”
“I particularly enjoyed testing myself in front of professionals from each field as well as receiving immediate feedback on my presentation skills. Fresh Science is an experience I strongly endorse to any ECR researcher (PhD students included) looking to improve their communication skills.”
Below: CNBP PhD student Marco Capelli talks nano materials at the Belgian Beer Cafe in Melbourne. Image courtesy of Science in Public (Fresh Science).
3 July 2017:
Researchers from CNBP’s RMIT University node (lead author CNBP PhD student Marco Capelli pictured), have had a paper published in the journal ‘Nanoscale’.
The researchers report an enhancement of the nitrogen-vacancy (NV) quantum yield by up to 7% in bulk diamond caused by an external magnetic field.
The paper is accessible online.
Publication title: Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield .
Authors: M. Capelli, P. Reineck, D. W. M. Lau, A. Orth, J. Jeske, M. W. Doherty, T. Ohshima, A. D. Greentree and B. C. Gibson.
Abstract: The nitrogen-vacancy (NV) centre in diamond is a unique optical defect that is used in many applications today and methods to enhance its fluorescence brightness are highly sought after. We observed experimentally an enhancement of the NV quantum yield by up to 7% in bulk diamond caused by an external magnetic field relative to the field-free case. This observation is rationalised phenomenologically in terms of a magnetic field dependence of the NV excited state triplet-to-singlet transition rate. The theoretical model is in good qualitative agreement with the experimental results at low excitation intensities. Our results significantly contribute to our fundamental understanding of the photophysical properties of the NV defect in diamond.
18 January 2017:
Researchers at CNBP’s RMIT University node were busy doing light-based demonstrations on Wednesday Jan 18th, as part of the ‘RMIT University Experience Day’ program, whereby students from years 10, 11 and 12 get to engage in hands-on workshops and explore life on campus while experiencing the differing aspects of University discipline areas.
As part of the ‘experience’ activity, over seventy high school students (predominantly in Year 10) visited the CNBP researchers in their physics laboratories. While there, students were given an overview of biophotonic science as well as laboratory research, and shown the exciting things that can be done with light including 3D scanning, fluorescence microscopy and more.
Below – CNBP researcher Philipp Reineck talks and demonstrates photonics to students.
5 December 2016:
A new publication from CNBP researchers (lead author Philipp Reineck pictured) demonstrates bright and photostable fluorescence from nitrogen-vacancy centers in unprocessed nanodiamond particle aggregates. The work has just been reported in the journal ‘Nanoscale’ and is accessible online.
Title: Bright and photostable nitrogen-vacancy fluorescence from unprocessed detonation nanodiamond.
Authors: P. Reineck, M. Capelli, D. W. M. Lau, J. Jeske, M. R. Field, T. Ohshim, A. D. Greentree and B. C. Gibson.
Abstract: Bright and photostable fluorescence from nitrogen-vacancy (NV) centers is demonstrated in unprocessed detonation nanodiamond particle aggregates. The optical properties of these particles is analyzed using confocal fluorescence microscopy and spectroscopy, time resolved fluorescence decay measurements, and optically detected magnetic resonance experiments. Two particle populations with distinct optical properties are identified and compared to high-pressure high-temperature (HPHT) fluorescent
nanodiamonds. We find that the brightness of one detonation nanodiamond particle population is on the same order as that of highly processed fluorescent 100 nm HPHT nanodiamonds. Our results may open the path to a simple and up-scalable route for
the production of fluorescent NV nanodiamonds for use in bioimaging applications.