Positron beam investigations of natural cubic and coated diamonds

A positron annihilation study on the defect properties of doped diamond films

“…The difference in the S and W absolute values in the first layer of the films may be caused by the different positron traps concentration, suggesting that positrons do not interact directly with the dopant S or B species. This is in agreement with previous results obtained on N-doped diamond [8] and B-doped diamond [6]. Also, the W-S characteristic value of the second layer of B-doped (100 Ω cm) sample is on the straight line (see Fig.…”

“…In recent years, PAS was successfully used to characterize the vacancies in pure and doped diamond films [3][4][5][6][7][8]. For nitrogen doped (N-doped) diamond, PAS indicated that the nitrogen-vacancy complex could influence the annihilation of positrons, while there was no strong interaction between the nitrogen atoms and positrons [7,8].…”

“…For nitrogen doped (N-doped) diamond, PAS indicated that the nitrogen-vacancy complex could influence the annihilation of positrons, while there was no strong interaction between the nitrogen atoms and positrons [7,8]. Boron doped (B-doped) diamond films were considered as an excellent electrode material, so that it was important to control its defect to improve the electrochemical performance.…”

Positron Spectroscopy of Nanodiamonds after Hydrogen Sorption

“…Taking into account the Tao–Eldrup model [ 32 , 33 ] we can estimate the radius of the pore to be equal to ~0.252 nm for the case of the non-hydrogenated samples. In addition, since the possibility of the formation of positronium in diamonds is still being discussed [ 34 ], we can assume that the formation of positronium is due to the large number of adsorbed gases and moisture because the measurements were carried out in air under normal conditions. For both samples (2,3) after the first loading of the hydrogen, the value of the τ o-Ps component was increased to the value of ~4.2 ns, however, its intensity practically did not change.…”

“…It should be noted that there is no component with lifetime 100–110 ps associated with the annihilation of positrons in the bulk of diamond [ 34 , 35 , 36 ]. For defect-free diamonds, the diffusion length is L diff = 162 nm [ 34 ]. Based on the fact that the average size of the nanodiamond is less than 10 nm ( Figure 4 ) the probability of positron annihilation from this state is negligible.…”