hafnium

noun

haf·​ni·​um ˈhaf-nē-əm 

: a metallic element that occurs especially in zirconium minerals and is used in control rods for nuclear reactors see Chemical Elements Table

Examples of hafnium in a Sentence

Recent Examples on the Web

The only way that the uranium-lead ratio can be compatible with the hafnium in the zircons, Whitehouse argued, is if the zircons that settled in the silt had crystallized around 2.8 billion years ago, constraining the organic carbon to being no older than that. —Howard Lee, ArsTechnica, 11 Aug. 2025

This coating is made up of a hafnium oxide layer frosted with a thin topping of zirconia oxide. —IEEE Spectrum, 28 July 2025

Heavy rare earths such as scandium and hafnium are particularly valued for their applications in clean energy, aerospace, and defense technologies. —Amala Balakrishner, CNBC, 10 June 2025

Boettcher’s group has its own strategy for protecting the membrane: coating the anode with a thin layer of hafnium oxide. —science.org, 23 Jan. 2025

Word History

Etymology

New Latin, from Hafnia (Copenhagen), Denmark

First Known Use

1923, in the meaning defined above

Kids Definition

hafnium

noun

haf·​ni·​um ˈhaf-nē-əm 

: a gray metallic element that is useful because of its ready absorption of neutrons see element

Medical Definition

hafnium

noun

haf·​ni·​um ˈhaf-nē-əm 

: a metallic element that resembles zirconium chemically, occurs in zirconium minerals, and readily absorbs neutrons

—symbol Hf see Chemical Elements Table