Hafnium (Hf)

Hafnium is a lustrous, silvery gray, tetravalent transition metal.

Core Principles & Analysis

• Dirk Coster and George de Hevesy discovered hafnium in 1923 in Copenhagen using X-ray spectroscopy, confirming a prediction of Niels Bohr.
• It is chemically almost identical to zirconium because of the lanthanide contraction, yet it absorbs neutrons hundreds of times more strongly.
• Hafnium forms control rods in naval nuclear reactors, and hafnium oxide became the high-k gate dielectric in modern microchip transistors.

Specifications & Metrics

• NUM: 72
• SYMBOL: Hf
• CATEGORY: Transition Metal