U3O8

triuranium octoxide · uranium oxide, yellowcake

U3O8 is a stable, semimetallic uranium oxide that acts as the primary industrial and commercial form for uranium storage and fuel fabrication.

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Crystal structure of U3O8
Ground-state structure · Materials Project
Overview

About triuranium octoxide

Triuranium octoxide is a robust, thermodynamically stable oxide of uranium that exists on the convex hull of stability. Its near-zero-gap electronic character distinguishes it as a semimetallic material, reflecting the complex interplay of its uranium oxidation states. This compound is the most stable form of uranium oxide under standard atmospheric conditions. It serves as the standard chemical form for the storage and transport of uranium, acting as a crucial intermediary in the production of nuclear reactor fuel. Its structural versatility is evidenced by the numerous distinct phases documented across materials databases.

At a glance

Key Properties

Cross-validated computational properties for triuranium octoxide, aggregated across 3 databases.

Band Gap

0.06 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

23
3 databases, 5 space groups
Uses

Applications

Where triuranium octoxide is used.

Nuclear fuel cycleUranium storageCeramic pigmentsNuclear fuel fabrication
Intellectual Property

Patent Landscape

4 patents reference U3O8 or close compositional variants.

PatentTitleAssigneeGranted
8628733Method for preparing uranium concentrates by fluidized bed precipitation, and preparation of UO3 and U3O8 by d
10106409Method for activating U3O8 with a view to converting same into hydrated UO4
8388895Apparatus for producing U3O8 powder
9045350Method for converting UO3 or U3O8 into hydrated UO4
Reference

Frequently Asked Questions

Common questions about triuranium octoxide, answered from cross-validated data.

What is U3O8?

U3O8 is a stable, semimetallic uranium oxide that acts as the primary industrial and commercial form for uranium storage and fuel fabrication.

More questions
What is U3O8 used for?
triuranium octoxide (U3O8) is used in nuclear fuel cycle, uranium storage, ceramic pigments, and nuclear fuel fabrication.
What is the band gap of U3O8?
triuranium octoxide (U3O8) has a DFT-computed band gap of 0.06 eV across 23 reported structures.
Is U3O8 a metal, semiconductor, or insulator?
With a near-zero band gap it behaves as a (semi)metal.
Is U3O8 thermodynamically stable?
Yes — triuranium octoxide (U3O8) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
How many polymorphs of U3O8 are known?
23 structures of U3O8 are reported across 3 databases, spanning 5 distinct space groups.
What elements does U3O8 contain?
triuranium octoxide (U3O8) contains O and U (2 elements).
Where does the data for U3O8 come from?
U3O8 data is cross-referenced from latticegraph.
Comparison

How It Compares

As a foundational oxide in the uranium-oxygen system, U3O8 represents the most stable equilibrium phase, serving as the benchmark against which other uranium oxides are evaluated for their structural and thermodynamic properties.

Data sources & attribution
  • latticegraph — Lattice Graph Materials Intelligence Platform

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