नाइओबियम बार

Properties

Atomic number

41

Atomic mass

92.91

Melting point

2 468 °C / 2 741 K

Boiling point

4 900 °C / 5 173 K

Atomic volume

1.80 ·  10-29 [m3]

Vapor pressure

at 1 800 °C

5 · 10-6 [Pa]

at 2 200 °C

4 · 10-3 [Pa]

Density at 20 °C

8.55 [g/cm3]

Crystal structure

body-centered cubic

Lattice constant

329.4 · 10-12 [m]

Hardness at 20 °C

formed 

110 - 180 [HV10]

recrystallized

60 - 110 [HV10]

Modulus of elasticity at 20 °C

104 [GPa]

Poisson number

0.35

Coefficient of linear thermal expansion at 20 °C

7.1 · 10-6 [m/(m·K)]

Thermal conductivity at 20 °C

52 [W/(m·K)]

Specific heat at 20 °C

0.27 [J/(g·K)]

Electrical conductivity at 20 °C

7 · 10-6 [1/(Ω·m)]

Specific electrical resistance at 20 °C

0.14 [(Ω·mm2)/m]

Sound speed at 20 °C

Longitudinal wave

4 920 [m/s]

Transverse wave

2 100 [m/s]

Electron work function

4.36 [eV]

Capture cross-section for thermal neutrons

1.15 · 10-28 [m2]

Recrystallization temperature (annealing time:1 hour)

850 - 1 300 [ °C]

Superconductivity (transition temperature)

< -263.95 °C / < 9.2 K