Observation of the $\frac{T}{(T-T_c)}$ Divergence of the ${\mu }^{+}$ Spin-Lattice Relaxation Rate in MnSi near $T_c$

The spin-lattice relaxation time ($T_1$) of the interstitial ${\mu }^{+}$ spin in the paramagnetic phase of a weak itinerant-electron helimagnet MnSi has been measured near the magnetic-ordering temperature in a 700-Oe longitudinal magnetic field. The observed temperature dependence of $\frac{1}{T_1}$ is represented very well by $\frac{T}{(T-T_c)}$ which was predicted on the basis of the self-consistent renormalization theory of spin fluctuations in itinerant-electron ferromagnets.