Lanthanum oxide

Lanthanum oxide (CAS 1312-81-8), also known as lanthana, lanthanum sesquioxide, or dilanthanum trioxide (La₂O₃), is a white, high-melting-point powder with a cubic crystal structure and a melting point of approximately 2,315 °C. It is a rare earth oxide in the lanthanum compounds group, registered under REACH in the 1,000–10,000 t/a tonnage band.

Where is Lanthanum oxide used?

• Electronics: dielectric additive in multilayer ceramic capacitors (MLCCs) and constituent of piezoelectric ceramics
• Optics: raw material for lanthanum crown and flint optical glasses in camera and smartphone lens systems
• Imaging: X-ray phosphor precursor
• Oil, gas and energy: primary feedstock for fluid catalytic cracking (FCC) catalyst formulations, stabilising the zeolite matrix under high-temperature regeneration
• Energy: precursor for solid oxide fuel cell (SOFC) electrolyte and electrode materials
• Automotive emission control: stabiliser for the alumina support in three-way catalyst (TWC) washcoats, suppressing sintering at exhaust operating temperatures
• Lubricants and metalworking: active oxide in lanthanum-doped tungsten TIG welding electrodes (WL15, WL20 grades), improving arc stability and electrode longevity compared with thoriated alternatives
• Specialty ceramic glazes and technical glass compositions require consistent chemistry batch to batch.

Good to know: It absorbs moisture from the air and converts progressively to lanthanum hydroxide (La(OH)₃), so proper dry storage is essential.

Commercial specifications

• Purities from 2N (≥ 99 % La₂O₃/TREO) to 5N (≥ 99.9999 % La₂O₃/TREO)
• TREO typically ≥ 98–99 %; loss on ignition (LOI) ≤ 1–2 %
• Particle size distributions d₅₀ 1–10 µm and −325 mesh typical for standard powder grades; nano-grade available
• Bulk packaging: 25 kg double PE-lined drums or bags, 500–1,000 kg big-bags; 4N and above in 1–5 kg sealed containers