Terbium(III) oxide

Terbium(III) oxide, also known as terbium sesquioxide, is a sesquioxide of the rare earth metal terbium, having chemical formula Tb
₂O
₃. It is a p-type semiconductor, which conducts protons, which is enhanced when doped with calcium.^[3] It may be prepared by the reduction of Tb
₄O
₇ in hydrogen at 1300 °C for 24 hours.^[4]

Tb₄O₇ + H₂ → 2 Tb₂O₃ + H₂O

Terbium(III) oxide

Names
IUPAC name terbium(III) oxide
Other names terbium trioxide, terbia, terbium sesquioxide
Identifiers
CAS Number	12036-41-8 Y
3D model (JSmol)	Interactive image
ECHA InfoCard	100.031.668
EC Number	234-849-5
PubChem CID	159410
CompTox Dashboard (EPA)	DTXSID401014252 DTXSID40276469, DTXSID401014252
InChI InChI=1/3O.2Tb/q3*-2;2*+3
SMILES [O-2].[O-2].[O-2].[Tb+3].[Tb+3]
Properties
Chemical formula	O3Tb2
Molar mass	365.848 g·mol−1
Appearance	white crystals
Density	7.91 g/cm3
Melting point	2,410 °C (4,370 °F; 2,680 K)
Magnetic susceptibility (χ)	0.07834 cm3/mol
Structure
Crystal structure	Cubic, cI80
Space group	Ia3, No. 206[1]
Lattice constant	a = 1.057 nm
Thermochemistry
Std molar entropy (S⦵298)	156.90 J/mol·K [2]
Std enthalpy of formation (ΔfH⦵298)	−1865.23 kJ/mol [2]
Gibbs free energy (ΔfG⦵)	−1776.553 kJ/mol [2]
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H319, H410
Precautionary statements	P264, P273, P280, P305+P351+P338, P337+P313, P391, P501
Related compounds
Other anions	Terbium(III) chloride
Other cations	Gadolinium(III) oxide Dysprosium(III) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

It is a basic oxide and easily dissolved to dilute acids, and then almost colourless terbium salt is formed.

Tb₂O₃ + 6 H⁺ → 2 Tb³⁺ + 3 H₂O

The crystal structure is cubic and the lattice constant is a = 1057 pm.^[5]