$^{69,71}$Ga NMR Probe of the Spin Dynamics in the Rare-Earth Kagom\'{e} Pr$_3$Ga$_5$SiO$_{14}$
ORAL
Abstract
We report $^{69,71}$Ga nuclear magnetic resonance investigation of the spin dynamics in the rare-earth kagom\'{e} system Pr$_3$Ga$_5$SiO$_{14}$. We find that the spin-lattice relaxation rate $^{69}1/T_1$ exhibits a peak around 30 K, below which the Pr$^{3+}$ spin correlation time $\tau$ shows novel field-dependent behavior consistent with a field-dependent gap in the excitation spectrum. The spin-spin relaxation rate $^{69}1/T_{2}$ exhibits a maximum at a lower temperature (10 K) below which field-dependent power-law behavior close to $T^{2}$ is observed. These results point to the interplay of single-ion anisotropy and field-induced formation of nanoscale magnetic clusters consistent with recent neutron scattering measurements.
*This work was supported in part by NSF DMR-0602859 and performed at the National High Magnetic Field Laboratory, which is supported by NSF Cooperative Agreement No. DMR-0084173, EIEG grant, by the State of Florida, and by the DOE.
–