NMR study of the charge-density wave inRb0.30MoO3single crystal

We present the first NMR study of the quasi one-dimensional conductor ${\mathrm{Rb}}_{0.3}$ ${\mathrm{MoO}}_3$. From the line shape of the ${}_{}{}^{87}{}_{}{}^{}\mathrm{Rb}$ first-order quadrupole satellite, we have studied the onset of the incommensurate charge-density wave at $T_I$=184 K and the temperature dependence of the order parameter. Our results demonstrate the crucial role played by impurities both on the normal incommensurate and the incommensurate-commensurate transition and give evidence for an interaction between the charge-density wave and mobile defects around $T_I$.