Nanodiamond synthesis by pulsed laser ablation in liquids

International audiencePulsed laser ablation in liquids (PLAL) has become an attractive method for the synthesis of nanodiamond. This work deals with the growth kinetics study of structures of nano-diamonds embedded in sp2 carbon synthetized by this method. The plasma created by the laser pulse has been monitored by time resolved spectroscopy to analyze the evolution of the plume and therefore the transient species created. Typical C2 vibrational bands appear, as well as a continuous spectrum due to various phenomena. The study of both the background and the vibrational features gives information on the reaction kinetics and on the plasma density. The presence of nanodiamonds has been confirmed by Raman spectroscopy as well as TEM analysis

Effect of Eu and Pb doping on the dosimetric properties of LiCAF

LiCaAlF6 (LiCAF) crystals doped with two different ions (europium and lead) have been investigated as potential new dosimetric materials. The stability of thermally stimulated luminescence (TSL) glow peaks in LiCAF:Eu was evaluated by means of the initial rise technique. The decay times at room temperature of the traps related to the dosimetric glow peaks were found to range between 40 and 2 7 104 years confirming the good dosimetric characteristics of this crystal. The glow curve of LiCAF:Pb is dominated by a peak at approximately 300 \ub0C emitting in the UV region (3P0,1\u20131S0 transition of Pb2+) superimposed to a very broad structure at lower temperature (20\u2013200 \ub0C) featuring recombination at an intrinsic defect centre. The anomalous behavior of the low temperature structure during thermal cleaning procedures prevented any reliable numerical analysis of the TSL glow peak at 300 \ub0C