We have studied the spin glass behaviour of non-superconducting La$_{ 2-x}$Sr$_x$Cu$_{ 0.95}$Zn$_{ 0.05}$O$_4$ ($x=0.10-0.22$). As in the superconducting analogues of these samples the spin glass transition temperature $T_g$ decreases with increasing $x$, and vanishes at $x=0.19$. A local enhancement in $T_g$ at $x=0.12$ is also observed and attributed to stripe ordering. The disappearance of $T_g$ for $x\geq0.19$ is discussed in terms of a quantum phase transition.
Categories: cond-mat.supr-con