Nuclear magnetic resonance linewidth and spin diffusion in ²⁹Si isotopically controlled silicon

A nuclear magnetic resonance (NMR) study was performed with n -type silicon single crystals containing S 29 i isotope abundance f ranges from 1.2% to 99.2%. The nuclear spin diffusion coefficient D has been determined from the linewidth of significantly enhanced S 29 i NMR signals utilizing a developed dynamic nuclear polarization (DNP) method. The S 29 i NMR linewidth depends linearly on f, at least when f<10%, and approaches ∝ f1/2 dependence when f>50%. The estimated S 29 i nuclear spin diffusion time Tsd between phosphorus atoms used for DNP is more than ten times shorter than the nuclear polarization time T1p of S 29 i nuclei around phosphorus. Therefore, the regime of "rapid spin diffusion" is realized in the DNP experiments.