Nanoscale freezing of the 2D spin liquid Pr${}_3$Ga${}_5$SiO${}_{14}$

In this letter, we report on the single crystal growth and physical characterization of the distorted kagom'{e} system Pr${}_3$Ga${}_5$SiO${}_{14}$. It is found that at zero magnetic field the system shows no magnetic order down to 0.035 K and exhibits a $T^2$ behavior for the specific heat at low temperatures, indicative of a gapless 2D spin liquid state. Application of an applied field induces nanoscale islands of ordered spins, with a concomitant reduction of the $T^2$ specific heat term. This state could be a possible ferro-spin nematic ordering stabilized out of an unusual spin liquid state.