Instability of Bubbles Near the Hadron--Quark-Gluon-Plasma Phase   Transition
  The small surface tension of the interface between hadronic and quark-gluon-plasma domains, along with a negative curvature tension, implies that the uniform plasma is unstable against spontaneous formation of hadronic bubbles. We furthermore show that spherical bubbles are not stable against small perturbations. 
Gideon Lana and Benjamin Svetitsky