terbium(III) oxide

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| verifiedrevid = 451892662

| ImageFile = Tl2O3structure.jpg

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| IUPACName = terbium(III) oxide

| OtherNames = terbium trioxide, terbia, terbium sesquioxide

| Section1 = {{Chembox Identifiers

| Abbreviations =

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 12036-41-8

| EINECS = 234-849-5

| PubChem = 159410

| SMILES = [O-2].[O-2].[O-2].[Tb+3].[Tb+3]

| InChI = 1/3O.2Tb/q3*-2;2*+3

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| ChEBI_Ref = {{ebicite|correct|EBI}}

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| Section2 = {{Chembox Properties

| Tb=2 | O=3

| Formula =

| MolarMass =

| Appearance = white crystals

| Density = 7.91 g/cm³

| MeltingPtC = 2410

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| Solubility =

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| MagSus = 0.07834 cm³/mol

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| Section3 = {{Chembox Structure

| CrystalStruct = Cubic, cI80

| SpaceGroup = Ia{{overline|3}}, No. 206{{cite journal| journal = J. Phys. F| year = 1973 | volume = 3| issue = 1 | pages = 1–5| title = The observation of face centred cubic Gd, Tb, Dy, Ho, Er and Tm in the form of thin films and their oxidation|doi=10.1088/0305-4608/3/1/009|author1=Curzon A.E. |author2=Chlebek H.G. | bibcode = 1973JPhF....3....1C }}

| LattConst_a = 1.057 nm

}}

| Section4 = {{Chembox Thermochemistry

| DeltaGf = −1776.553 kJ/mol R. Robie, B. Hemingway, and J. Fisher, "Thermodynamic Properties of Minerals and Related Substances at 298.15K and 1bar Pressure and at Higher Temperatures," US Geol. Surv., vol. 1452, 1978.[https://pubs.usgs.gov/bul/1452/report.pdf]

| DeltaHc =

| DeltaHf = −1865.23 kJ/mol

| Entropy = 156.90 J/mol·K

| HeatCapacity =

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| Section7 = {{Chembox Hazards

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| GHSPictograms = {{GHS07}}{{GHS09}}

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|319|410}}

| PPhrases = {{P-phrases|264|273|280|305+351+338|337+313|391|501}}

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| Section8 = {{Chembox Related

| OtherAnions = Terbium(III) chloride

| OtherCations = Gadolinium(III) oxide
Dysprosium(III) oxide

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Terbium(III) oxide, also known as terbium sesquioxide, is a sesquioxide of the rare earth metal terbium, having chemical formula {{chem|Tb|2|O|3}}. It is a p-type semiconductor, which conducts protons, which is enhanced when doped with calcium.{{cite journal|journal=Solid State Ionics|volume=176|issue=39–40|date=December 2005|pages=2957–2961|doi=10.1016/j.ssi.2005.09.030|publisher=Elsevier B.V.|title=Proton conductivity of Ca-doped {{chem|Tb|2|O|3}}|author1=Reidar Haugsrud |author2=Yngve Larring |author3=Truls Norby |name-list-style=amp }} It may be prepared by the reduction of Terbium(III,IV) oxide in hydrogen at 1300 °C for 24 hours.{{cite journal|journal=Journal of Applied Crystallography|volume=4|issue=5|date=October 1971|pages=399–400|doi=10.1107/S0021889871007295|title=Crystal data on C-type terbium sesquioxide ({{chem|Tb|2|O|3}})|author=G. J. McCarthy}}

:{{chem2|Tb4O7 + H2 -> 2 Tb2O3 + H2O}}

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.N. C. Baenzinger, H. A. Eick, H. S. Schuldt, L. Eyring: Terbium Oxides. III. X-Ray Diffraction Studies of Several Stable Phases. In: Journal of the American Chemical Society, 1961, 83, 10, S. 2219-23.