Stretched exponential relaxation of stress-induced quadrupolar order is found in Ko.989Lio.onTa03 at temperatures T < 30 K. In contrast to expectations for glasses, however, the stretching exponent increases upon cooling and reaches unity as T-• 0. In parallel with the observed loss of polydispersivity the relaxation time crosses over from Arrhenius to dissipative-quantum-tunneling behavior, r(T) = T(0)exp( -aT 4 ) at T < 20 K. The absence of quadrupolar freezing seems to be due to the onset of tunneling and to coupling with the frozen-in dipolar degrees of freedom.
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