A chemical element with the symbol Hf and atomic number 72.
A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals.
Hafnium is used in filaments, electrodes, and some semiconductor fabrication processes for integrated circuits at 45 nm and smaller feature lengths.
Some superalloys used for special applications contain hafnium in combination with niobium, titanium, or tungsten.
