Muon spin relaxation and susceptibility studies of the pure and diluted spin 1/2 kagomé-like lattice system (CuxZn(1-x))3V2O7(OH2) 2H2O.

Muon spin relaxation and magnetic susceptibility measurements have been performed on the pure and diluted spin ½ kagome system (Cu x Zn 1 - x ) 3 V 2 O 7 (OH) 2 2H 2 O. In the pure x = 1 system we found a slowing down of Cuspin fluctuations with decreasing temperature towards T ∼ 1 K, followed by slow and nearly temperature-independent spin fluctuations persisting down to T = 50 mK, indicative of quantum fluctuations. No indication of static spin freezing was detected in either of the pure (x = 1.0) or diluted samples. The observed magnitude of fluctuating fields indicates that the slow spin fluctuations represent an intrinsic property of kagome network rather than impurity spins.