Question

Which metals contract when temperature is increased? Which compound so negative thermal expansion?

Answer 1

Zirconium tungstate is the compound which contract when heated.
Most solids expand when heated, a familiar phenomenon with many practical implications. Among the rare exceptions to this rule, the compound zirconium tungstate stands out by virtue of the enormous temperature range over which it exhibits so-called "negative thermal expansion," contracting as it heats up and expanding as it cools, and because it does so uniformly in all directions

Zirconium tungstate is the only compound having negative thermal expansion.No metal will contract when heated