▎ 摘　　要

Weak-localization (WL) measurements were performed in a Bi cluster-decorated graphene sheet. The charge concentration was kept constant, and the amplitude of the conductance correction was suppressed after the Bi-cluster deposition. Detailed WL data were obtained while the gate and temperature were changed. Using E. McCann's formula, the spin-relaxation time was extracted, which was found to increase with the elastic scattering time. This is attributed to the Elliott-Yafet spin relaxation and Kane-Mele type spin-orbit coupling (SOC). The SOC strength was enhanced to 2.64 meV as a result of the first deposition. The coverage effect is discussed according to the measurement after the second deposition.