  In itinerant magnetic systems with disorder, the quantum Griffiths phase at
T=0 is unstable to formation of a cluster glass (CG) of frozen droplet degrees
of freedom. In the absence of the fluctuations associated with these degrees of
freedom, the transition from the paramagnetic Fermi liquid (PMFL) to the
ordered phase proceeds via a conventional second-order quantum phase
transition. However, when the Griffiths anomalies due to the broad distribution
of local energy scales are included, the transition is driven first-order via a
novel mechanism for a fluctuation induced first-order transition. At higher
temperatures, thermal effects restore the transition to second-order.
Implications of the enhanced non-Ohmic dissipation in the CG phase are briefly
discussed.
