Element 72 in our International Year of the Periodic Table series is hafnium. Hafnium is used in reactors in nuclear submarines and also helps make microchips smaller and faster.

Hafnium is a neutron absorber and is used in nuclear reactor control rods in nuclear submarines. Its absorption cross-section for absorbing neutrons is about 600 times that of zirconium, another element commonly used in reactor control rods.

Hafnium oxide is used for electrical insulators in microchips, which control the flow of electricity through the transistors on the chip. This, in turn, allows for the chips to be made smaller and faster.

Hafnium is corrosion-resistant and also has a high melting point. The latter property means that it is used in some plasma cutting tips and welding torches.

Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.