Exploring the Properties and Applications of Niobium Oxide

Niobium and oxygen can form five oxides: NbO, NbO2, Nb2O, Nb6O and Nb2O5, of which only Nb2O5 is the most stable, and niobium pentoxide exists in the structure of niobium oxygen hexahedron.

Physical and chemical properties of niobium oxide

Appearance: white powder, odorlessDensity: 4.47 g/mL at 25ºC(lit.)

Melting point: 1520ºC

Molecular formula: Nb2O5

Molecular weight: 265.81000

Solubility: Insoluble in water, soluble in molten potassium hydroxide and potassium sulfate, also soluble in carbonates of alkali metals and Hydroxide, as well as hydrofluoric acid and hot sulfuric acid.

Properties and Stability of Niobium Oxide

If used and stored according to the specifications, it will not decompose, has no known dangerous reactions, and avoids oxidation. Insoluble in water, hardly soluble in acid, soluble in molten potassium bisulfate or alkali metal carbonate, hydroxide. Niobium pentoxide is heat stable. Near the melting point and during melting, only a small amount of NbO2 and O2 are dissociated. It belongs to the α□U3O8 structure of the orthorhombic system.

Niobium Oxide Synthesis Process

1. Roasting method Dissolve niobium material or crude niobium pentoxide in a mixed solution of nitric acid and hydrofluoric acid to generate fluoroniobic acid, extract niobium with strong acid and methyl isobutyl ketone organic phase mixed solution, and then strip it with ammonia water React with fluoroniobic acid to form niobium hydroxide precipitate, and then wash, dry and burn to obtain refined niobium pentoxide.

3Nb+5HNO3+21HF→3H2NbF7+5NO+10H2O

H2NbF7+7NH4OH→Nb(OH)5+7NH4F+2H2O

2Nb(OH)5→Nb2O5+5H2O

2. Heating and dehydrating pentavalent niobium hydroxide (niobic acid), or burning metal niobium, niobium carbides, nitrides, sulfides, etc. in air can also obtain niobium pentoxide.

The role and use of niobium oxide

1. Used as nickel niobate single crystal to make special optical glass, high-frequency and low-frequency capacitors and piezoelectric ceramic components. It is also used in the production of ferroniobium and various niobium alloys required for special steel. It is the raw material for producing niobium and its compounds. It is also used as catalyst and refractory material. 

2. It is the raw material for manufacturing ceramic capacitors, niobium salts and metal niobium. It is used as a piezoelectric conductor material in the electronics industry and is also used to prepare standard solutions.

Niobium Oxide Capacitor Characteristics

The basic electrical characteristics of NbO capacitors include: capacity range: 10µF~470µF, rated up to 1000µF, and the case size conforms to the A to E standards of EIA (American Electronics Industries Association). The reliability of AVX's OxiCapGeneric series NbO capacitors is 0.5%/1000 hours (twice that of tantalum capacitors), and the reliability of the Performance series is 0.2%/1000 hours. Reliability NbO capacitors have very effective self-healing properties and thus guarantee superior reliability over other commercially available capacitor technologies. The Performance series has reliability specifications as high as 0.2%/1000 hours, such as 500000 hours MTBF (mean time to failure). The reliability of the Generic series is 0.5%/1000 hours, eg 200000 hours MTBF. This level of reliability is higher than most existing commercial grade capacitors.

Niobium oxide storage 

Store in a ventilated, dry place, not stacked in the open air.