Molybdenum characteristics
What is molybdenum?
1High melting point
Molybdenum has the fifth highest melting point among metals. It has a low thermal expansion coefficient and extremely high shape stability even under high temperature environments.
2Large electric resistance
Molybdenum has relatively large electric resistance. We offer it as a heater for high-temperature furnaces and electrodes for lighting.
3Easy workability
Molybdenum, which has relatively easy workability among high melting point metals, can be applied for complex shapes such as boxes and meshes.
Hard, silver white molybdenum, named from the ore molybdenite by K. W. Schale of Sweden, is one of the rare metals.
Molybdenum is often used as an additive for steel materials. Using its characteristics – high melting point, excellent mechanical features, relatively easy workability compared to tungsten, etc. – it is an Indispensable metal in various applications: ribbon and wire in the field of lighting; and semiconductor substrates, glass melting electrodes, heaters and reflectors in high-temperature furnaces, and sputtering targets as wiring materials for solar cells and flat panels in the field of power electronics.
| Atomic number | 42 | |
|---|---|---|
| Density （Mg/cm3） |
293K | 10.28 |
| Melting point（K） | 2,890 | |
| Boiling point（K） | 4,885 | |
| Vapor pressure （Pa） |
2000K | 3・10-5 |
| Resistivity （10-8Ωm） |
300K | 5.2 |
| Specific heat （J/kg・K） |
273K～373K | 259 |
| Thermal conductivity（W/m・K） | 300K | 138 |
| Linear expansion coefficient （10-6/K） |
293 293～2000K |
4.8 6.7 |
| Work function （eV） |
Single crystal Polycrystal |
4.6 |
| Thermal neutron capture cross section area （10-28m2） |
300K | 2.60 |
Chemical properties
- In the air, oxidation starts at room temperature, proceeding considerably in the dark red temperature.
- Molybdenum does not react at room temperature with dried oxygen, but it rapidly oxidizes at 500℃ or higher, and it evaporates at 650℃ or higher turning into MoO3 of white mouse color.
- It reacts with sulfur, carbon or silicon easily at high temperature to produce MoS₂, Mo₂C, MoSi₂, etc.
- Nitrogen gradually dissolves into molybdenum from 600℃ and reacts extremely at 1,200℃, producing a fragile compound. Nitride is produced at 1,500℃ or higher.
- The affinity for arsenic is strong.
- It corrodes little in hydrofluoric acid, hydrochloric acid and sulfuric acid at 20 ℃, but corrodes significantly in nitrate, high concentration sulfate (250 ℃) and aqua regia.
| Substance | Temperature | Reaction |
|---|---|---|
| Air | 200℃ | Oxidizes a little |
| ≧400℃ | Produces MoO3 | |
| Oxygen | 200℃ | Oxidizes a little |
| ≧400℃ | Produces MoO3 | |
| Vapor | ≧700℃ | Oxidizes |
| Nitrogen | ≧1,500℃ | Produces nitrides |
| Carbon monoxide | ≧1,400℃ | Produces carbides |
| Carbon dioxide | 1,200℃ | Oxidizes |
| Hydrocarbon | 1,100℃ | Carbonizes |
| Chlorine | 250℃ | Produces chloride |
| Bromine | 250℃ | Produces bromide |
| Iodine | 800℃ | No reaction |
| Hydrogen |
All temperature |
No reaction |
| Hydrogen sulfide | 1,200℃ | Produces MoS2 |
| Sulfur dioxide | 600℃ |
Produces MoO2 |
|
Nitrous oxide |
600℃ | Produces MoO3 |
| Ammonia | No reaction |
| Substance | Temperature | Reaction |
|---|---|---|
| Carbon | ≧1,100℃ | Carbonizes |
| Magnesia | 1,600℃ | Reaction |
| Zirconia | 2,200℃ | Reaction |
| Thoria | 1,900℃ | Reaction |
| Alumina | 1,900℃ | No reaction |
| Sulfur | 600℃ | Corrodes |
| Tungsten | 2,000℃ | Reaction |
| Beryllia | up to 1,900℃ | Reaction |
| Substance | Temperature | Reaction |
|---|---|---|
| Aluminum | 600℃ | Stable |
| Beryllium | Not stable | |
| Lead | up to 1,200℃ | Stable |
| Lead (with oxygen) | up to about 500℃ | Stable |
| ≧500℃ | Not stable | |
| Cesium | up to 870℃ | Stable |
| ≧870℃ | Not stable | |
| Iron | Not stable | |
| Gallium | up to 400℃ | Stable |
| Gold | Stable | |
| Potassium | up to 1,200℃ | Stable |
| Cobalt | Not stable | |
| Copper | up to 1,300℃ | Stable |
| Lithium | up to 1,400℃ | Stable |
| Magnesium | up to 1,000℃ | Stable |
| Sodium | up to 1,030℃ | Stable |
| Sodium (0.5％ oxygen) | up to 400℃ | Stable |
| ≧400℃ | Not stable | |
| Nickel | Not stable | |
| Plutonium | Stable | |
| Mercury | up to 600℃ | Stable |
| ≧600℃ | Not stable | |
| Rubidium | up to 1,000℃ | Stable |
| Scandium | Not stable | |
| Rare metal | up to 1,100℃ | Stable |
| ≧1,400℃ | Not stable | |
| Silver | Stable | |
| Thallium | Not stable | |
| Uranium | Not stable | |
| Bismuth | up to 1,400℃ | Stable |
| Zinc | up to 500℃ | Stable |
| ≧500℃ | Not stable | |
| Tin | up to 520℃ | Stable |
| ≧520℃ | Not stable |
| Substance | Temperature | Reaction |
|---|---|---|
| Water |
Room |
No reaction |
| Hot liquid | No reaction | |
| 10％ hydrochloric acid | Room temperature |
0.0355 |
| Heating | 0.2794 | |
| Dilute sulfuric acid | 110℃ | 20.1168 |
| Concentrated sulfuric acid | 110℃ | 0.3378 |
| 10％ sulfuric acid | Room temperature |
0.0203 |
| Heating | 0.1066 | |
| Concentrated sulfuric acid | 110℃ | 0.2870 |
| 10％ nitric acid | Room temperature |
18.5420 |
| Heating | 154.94 | |
| Hydrofluoric acid | Room temperature |
Corrodes |
| 10％ phosphoric acid | Room temperature |
0.1066 |
| Heating | 0.7721 | |
| 10％ acetate | Room temperature |
0.0711 |
| Heating | 0.2565 | |
|
Sulfuric acid ＋hydrofluoric acid |
Rapidly corrodes | |
|
Sulfuric acid ＋hydrochloric acid |
Rapidly corrodes | |
|
Sulfuric acid ＋sulfuric acid |
Rapidly corrodes | |
|
Sodium hydroxide |
up to 100℃ | Stable |
| Sodium hydroxide ≧50％ |
up to 100℃ | Not stable |
| Ammonium hydroxide | Not stable | |
| Potassium hydroxide ≦50％ |
up to 100℃ | Stable |
| Potassium hydroxide ≧50％ |
up to 100℃ | Not stable |