Hafnium was predicted to exist by Mendeleev but it was not until 1911 that Georges Urbain, the discoverer of Lutetium, thought he had discovered Hafnium but it was not to be. It was just a mixture of lanthanides. It was in 1923 that Georg Von Hevesy and Dirk Coster discovered Hafnium by x-ray spectroscopy of Zirconium ores. It is named after the latin ‘Hafnia’ the Latin for the city of Copenhagen. It is used in nuclear control rods to absorb neutrons and is corrosion resistant. Hafnium is not found free in nature but mostly in zirconium ores. It is a solid metal at room temperature with a melting point of 2233°c and a boiling point of 4602°c.
Dirk Coster, Georg von Hevesy