http://www.physorg.com/news4102.html

There is another reason for the speed increase, it is that the atoms have moved closer together or physically shrunk. This is just like the ice skater who spins slowly with outstreched arm and moves very much faster as the arm are drawn into the body.

It is also being assumed here that atoms are spherical, if they are not and spinning, greater space is required for each assembly. if when all the heat is removed they stop spinning this will give more room for the structures to encroach into the space of each other. It is probably the spinning nature that prevents them from being superfluid at higher temperatures.

AR