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ytterbium oxide

n. (context inorganic compound English) Any oxide of ytterbium, but especially the colourless solid Yb2O3 (itterbia or ytterbia)

Wikipedia
Ytterbium(III) oxide

Ytterbium(III) oxide is the chemical compound with the formula YbO. It is one of the more commonly encountered compounds of ytterbium. It has the "rare-earth C-type sesquioxide" structure which is related to the fluorite structure with one quarter of the anions removed, leading to ytterbium atoms in two different six coordinate (non-octahedral) environments.