Lanthanum Oxide La2O3

Lanthanum Oxide, La2O3,cerium oxide.La2O3,TREO,Pr6O11, CAS No.: 1312-81-8

Lanthanum Oxide,La2O3,

Molecular formula La2O3 Molar mass 325.81 g/mol Appearance White powder, hygroscopic Density 6.51 g/cm3, solid Melting point 2315 'C (2588 K)Boiling point 4200 'C (4500 K)Solubility in water Insoluble

CAS No.: 1312-81-8

           spec          typicalTREO:     97% min.        98.5%La2O3/TREO: 99.9% min.    99.95%   CeO2/ TREO: 0.025% max.    0.01% Pr6O11/TREO: 0.025% max.   0.01%Nd2O3/TREO: 0.015% max.    0.01%  Sm2O3/TREO: 0.02% max.   0.003%Y2O3/TREO: 0.01% max.    0.001%Fe2O3:    0.02% max.      0.008%CaO:      0.20% max.      0.07% Cl:       0.10% max.      0.06%SiO2:     0.03% max.      0.03%L.O.I.:    3% max.        1.2%

Other cations Scandium(III) oxideYttrium(III) oxideActinium(III) oxide Related compounds Lanthanum aluminium oxide,LaSrCoO4

La2O3 has largest of the rare earth oxides at 4.3 eV, while also having the lowest lattice energy, with very high , ε = 27. La2O3 is widely used in industry as well as in the research laboratory. Lanthanum oxide is an odorless, white solid that is insoluble in water, but soluble in dilute acid. Depending on the pH of the compound, different crystal structures can be obtained. Lanthanum oxide has p-type semi-conducting properties because its resistivity decreases with an increase in temperature, average room temperature resistivity is 10 kΩ·cm.

Synthesislanthanum oxide crystallizes as several polymorphs.

To produce hexagonal La2O3, a 0.1 M solution of LaCl3 is sprayed onto a preheated

substrate, usually made of metal chalcogenides.[3] The process can be viewed as occurring

in two steps – hydrolysis followed by dehydration:

2 LaCl3 + 3 H2O → La(OH)3 + 3 HCl2 La(OH)3 → La2O3 + 3 H2OAn alternative route to hexagonal La2O3 involves precipitation of nominal La(OH)3 from

aqueous solution using a combination of 2.5% NH3 and the surfactant sodium dodecyl sulfate

followed by heating and stirring for 24 hours at 80 °C:

2 LaCl3+ 3 H2O + 3 NH3 → La(OH)3 + 3 NH4ClLaCl3·3H2O → La2O3Other routes include:

2 La2S3 + 3 CO2 → 2 La2O3 + 3 CS22 La2(SO4)3 + heat → 2 La2O3 + 6 SO3

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Lanthanum Oxide La2O3