Niobium
transition metalProperties
| Property | Value |
|---|---|
| Atomic Mass | 92.906 amu |
| Category | transition metal |
| Group | 5 |
| Period | 5 |
| Electron Configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d4 |
| Electronegativity | 1.6 (Pauling) |
| Oxidation States | 5, 3, 2 |
| Melting Point | 2750 K (2476.8 °C) |
| Boiling Point | 5017 K (4743.9 °C) |
| Density | 8.57 g/cm³ |
| Discovered By | Charles Hatchett (1801) |
About Niobium
Niobium is the type-II superconductor that actually pays the bills. Below 9.25 K it goes superconducting, and the alloys Nb-Ti (Tc ~10 K, Hc2 ~15 T) and Nb₃Sn (Tc 18 K, Hc2 ~30 T) are what wind every clinical MRI magnet, the LHC dipoles at CERN, and the toroidal field coils being built for ITER. Above the cryogenic range its other personality kicks in: 0.05% Nb in low-carbon steel precipitates as NbC and pins grain boundaries, raising yield strength by 30% with no loss of weldability — the basis of the HSLA pipeline steels that move oil and gas across continents. The element is chemically Ta's near-twin (same group, almost identical ionic radius thanks to the lanthanide contraction), which is why Hatchett's 1801 discovery from a Connecticut columbite specimen was disputed for decades; the name niobium (after Niobe, daughter of Tantalus) eventually settled the matter in 1949. Brazil's Araxá deposit supplies about 85% of world production from a single pyrochlore mine.
Fun Fact
About 80% of the world's niobium comes from a single pyrochlore deposit in Araxá, Brazil. CBMM, the operator, ships ferroniobium briquettes that go into nearly every grade of high-strength low-alloy steel — pipeline, automotive, structural — usually at concentrations under 0.05%.
Common Uses
- Nb-Ti and Nb₃Sn superconducting wire for MRI and accelerator magnets
- Microalloying addition (~0.05%) in HSLA pipeline and structural steels
- Niobium-stabilized superalloys (Inconel 718) for jet engine turbine disks
- Tantalum-replacement electrolytic capacitors in consumer electronics
- Anodized niobium for hypoallergenic body jewelry and surgical implants