Terbium(III) oxide, also known as terbium sesquioxide, is a

sesquioxide A sesquioxide is an oxide of an Chemical element, element (or Radical (chemistry), radical), where the ratio between the number of atoms of that element and the number of atoms of oxygen is 2:3. For example, aluminium oxide and phosphorus(III) oxi ...

of the rare earth metal

terbium Terbium is a chemical element with the symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, and ductile. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with w ...

, having

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

. It is a p-type

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

, which conducts protons, which is enhanced when doped with

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

. It may be prepared by the reduction of in

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

at 1300 °C for 24 hours. : 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 A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has o ...

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 The ''Journal of the American Chemical Society'' is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society. The journal has absorbed two other publications in its history, the ''Journal of Analytic ...

'', 1961, 83, 10, S. 2219-23.

References

Terbium compounds Sesquioxides Semiconductor materials {{inorganic-compound-stub