What element on the periodic table is named after the European capital where it was discovered in 1923?
Origin of name: from the Latin name “Hafnia” meaning “Copenhagen”. Hafnium was thought to be present in various zirconium minerals many years prior to its discovery, in 1923, which was credited to Dirk Coster and George Charles von Hevesey.
Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalenttransition metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, making it the penultimate stableelement to be discovered (rhenium was identified two years later). Hafnium is named after Hafnia, the Latin name for Copenhagen, where it was discovered.
Hafnium is used in filaments and electrodes. Some semiconductor fabrication processes use its oxide 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.
Hafnium’s large neutron capture cross-section makes it a good material for neutron absorption in control rods in nuclear power plants, but at the same time requires that it be removed from the neutron-transparent corrosion-resistant zirconium alloys used in nuclear reactors.