Author/Authors :
A.I. Shames، نويسنده , , A.M. Panich، نويسنده , , W. Kempi?ski، نويسنده , , A.E. Alexenskii، نويسنده , , M.V Baidakova، نويسنده , , A.T. Dideikin، نويسنده , , V.Yu. Osipov، نويسنده , , V.I. Siklitski، نويسنده , , E. Osawa، نويسنده , , M. Ozawa، نويسنده , , A.Ya. Vul’، نويسنده ,
Abstract :
EPR, 13C NMR and TEM study of ultradisperse diamond (UDD) samples is reported. The compounds show a high concentration of paramagnetic centers (up to 1020 spin/g), which are due to structural defects (dangling C–C bonds) on the diamond cluster surface. The anomalous reduction in the spin–lattice relaxation time of 13C (from several hours in natural diamond to ∼150 ms in UDD clusters) is attributed to the interaction between the unpaired electrons of the paramagnetic centers and nuclear spins. 13C NMR line-width reflects the fact that the structure of the UDD surface is distorted in comparison to the ‘bulk’ diamond structure.
