hafnium

American  

[haf-nee-uhm, hahf-] / ˈhæf ni əm, ˈhɑf- /

noun

Chemistry.

1. a gray, toxic metallic element with a high melting point (over 2000°C), found in most zirconium minerals. Hf; 178.49; 72; 12.1.

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hafnium British  

/ ˈhæfnɪəm /

noun

1. a bright metallic element found in zirconium ores: used in tungsten filaments and as a neutron absorber in nuclear reactors. Symbol: Hf; atomic no: 72; atomic wt: 178.49; valency: 4; relative density: 13.31; melting pt: 2231±20°C; boiling pt: 4603°C

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hafnium Scientific  

/ hăf′nē-əm /

1. A bright, silvery metallic element that occurs in zirconium ores. Because hafnium absorbs neutrons better than any other metal and is resistant to corrosion, it is used to control nuclear reactions. Atomic number 72; atomic weight 178.49; melting point 2,220°C; boiling point 5,400°C; specific gravity 13.3; valence 4.

2. See Periodic Table

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Etymology

Origin of hafnium

1923; < New Latin Hafn ( ia ) Copenhagen + -ium

Example Sentences

"In our study, we show that isolated indium atoms on hafnium oxide allow more efficient CO2-based methanol synthesis than indium in the form of nanoparticles containing large numbers of atoms."

From Science Daily • Mar. 20, 2026

Woodhead and colleagues present a compilation of newly acquired and previously published neodymium and hafnium isotopic data, measured on archetypal kimberlites.

From Nature • Sep. 24, 2019

One notable example was the discovery of three particularly rare elements found — hafnium, uranium and tungsten.

From Fox News • Aug. 1, 2019

Control rods are made of boron, cadmium, hafnium, or other elements that are able to absorb neutrons.

From Textbooks • Feb. 14, 2019

In its very center, buried in a mine of graphite were the tubes of hafnium, from whose nuclear explosions flowed a river of electricity without the need of human thought or direction.

From The Stutterer by Merliss, R. R.