Longitudinal field muon spin relaxation (LF-μSR) measurements and evidence for a new muonium defect site in type Ia diamond

A new configuration for muonium, with hyperfine interaction parameters of less than axial symmetry, in nitrogen rich diamond is identified in Longitudinal Field Muon Spin Relaxation (LF-mu SR) measurements. The TF-mu SR measurements on the same sample show that almost the entire strength of the new configuration is accounted for by a "missing fraction", typically seen in nitrogen rich type Ia diamond. The "missing fraction" is therefore the result of a T2 relaxation. This is consistent with muon trapping at or in some nitrogen related defect(s) followed by electron capture at random times

Interplay of mean field and nucleon-nucleon interactions in the production of carbon fragments in <SUP>16</SUP>O induced reactions at incident energies up to 25 MeV/amu

NatuurwetenskappeFisikaPlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Diamond biosensors

International audienceDiamond is wide band gap semiconductor presenting many extreme properties. It is notably known as the most stable material with the highest chemical inertness, the highest mechanical hardness and the highest thermal conductivity. Since the mid 1970s it has been possible to grow synthetic diamond by several methods. High Pressure High Temperature techniques that mimic the diamond formation in the earth's crust were first developed. Then Chemical Vapour Deposition (CVD) methods enable diamond growth at laboratory scale as well as the control the P-type and N-type doping of diamond. Besides, it is possible to tune the diamond electrical properties form very resistive to metallic thanks to the P-type doping with boron. Current achievements have enabled the development of diamond sensors that can operate in extreme conditions. After being used for its mechanical and thermal properties, diamond was considered for chemical sensing. In fact the chemical stability and the close-to-metallic conductivity of diamond make it a powerful tool for electrochemical detection in various environment. Furthermore, the diamond is an ideal substrate for surface functionalization thanks to the wide and very known carbon based chemistry. Such a feature combined to the outstanding electrochemical properties of the diamond electrodes have enable the production of very efficient biosensors and biochips. Diamond is also an interesting sensor for medical imaging. Its carbon nature, well tolerated by living tissues, are actually very useful for its use as a biosensor capable of working in contact with bio-environments as well as real neuronal interfaces. Both those topics will be discussed in details in the following pages. In a first part an overview on electrochemical based biosensors and their performance is described. Then in a second half of the chapter, novel applications where diamond is directly used as an electrode for neural tissue interfacing is presented in details