Germanium Oxide, Germanium Dioxide, 1310-53-8

Didymium Oxide, 11141-21-2

🧪 Didymium Oxide (CAS 11141-21-2)

Didymium oxide is not a single-element oxide but rather a mixture of neodymium and praseodymium oxides, historically referred to as “didymium” before these rare-earth elements were separated. It typically appears as a brown crystalline powder, insoluble in water but soluble in acids, and is valued for its optical absorption properties.

1️⃣ Chemical Identity

• Chemical Name: Didymium Oxide

• Formula: Mixed oxide (Nd₂O₃ + Pr₆O₁₁)

• Molecular Weight: ~666 g/mol (varies with composition)

• CAS Number: 11141-21-2

• Appearance: Brown powder

• Solubility: Insoluble in water; soluble in acids

2️⃣ Physical & Chemical Properties

• Color: Brown to reddish-brown crystalline powder

• Stability: Stable under normal conditions

• Reactivity: Dissolves in acids to form rare-earth salts

• Optical Properties: Strong absorption bands in the visible spectrum, useful for optical filters

3️⃣ Applications

• Glass Industry:

  • Used for coloring and decolorizing glass

  • Provides selective absorption in optical lenses and welding goggles

• Electronics:

  • Incorporated in temperature-compensating capacitors for radios, televisions, and radar systems

• Metallurgy:

  • Applied in stainless steel production and metallurgical research

• Textiles:

  • Used in specialized textile treatments

• Carbon Arc Lamps:

  • Utilized in carbon-arc cores (fluoride type)

4️⃣ Synonyms

• Didymium Oxide

• Mixed Rare-Earth Oxide (Nd–Pr)

• Neodymium–Praseodymium Oxide

5️⃣ Safety & Handling

• Hazards: Generally considered non-hazardous under standard chemical safety guidelines

• Precautions: Use gloves, goggles, and dust masks when handling powders

• Storage: Store in sealed containers, dry environment, ideally at 2–8 °C

📌 Summary: Didymium Oxide (CAS 11141-21-2) is a rare-earth mixed oxide of neodymium and praseodymium, appearing as a brown powder. It is widely used in glass coloring, optical filters, capacitors, metallurgy, and textiles, with relatively low hazard classification.