Electron Paramagnetic Resonance Study on a 28Si Single Crystal for the Future Realization of the Kilogram

In the future realization of the kilogram using the x-ray crystal density method, isotopically enriched silicon crystals grown by the floating zone method are employed. In this paper, we present the electron paramagnetic resonance study on
²⁸
Si single crystal AVO28. We revealed that the concentrations of various kinds of vacancy defects in the crystal are less than 1×10
¹²
cm
^-3
. Consequently, the necessary mass deficit correction due to these vacancy defects is estimated to be less than 0.4 μg for 1 kg AVO28 spheres.