Contracting metal

Does anyone know the name of a metal which contracts when
heated? Is there such a material? Apparently it behaves similarly
to heat shrink plastic. Any would be appreciated.
Thanks Valerie.

Could you be thinking of PMC (precious metal clay)? It shrinks
considerably, approximately 40% in a kiln.

Could you be thinking of “reticulating silver” This kind of
silver has a higher content of copper and wrinkles when heated.
(It appears to be “shrinking”)

In the electronic instrument industry a company named Foxboro
had a line of indicators that had a wire to drive the pointer
needle on an indicator. The wire would contract when heated by
electric current. I believe the wire was called Nitonal.

Stephan