Cobalt

Cobalt is a hard, lustrous, silver-gray metal with the symbol Co and atomic number 27. It has an atomic weight of 58.933195 u and a density of 8.9 g/cm3. Cobalt has a high melting point of 1495°C and boiling point of 2927°C. It commonly occurs in the +2 and +3 oxidation states. Cobalt can be found in ores like cobaltite (CoAsS) but is mainly produced as a by-product of copper and nickel mining.

Cobalt has many important applications in electronics and magnetics. It is a key component of lithium-ion battery cathodes in most mobile phones and laptops. The addition of cobalt improves the energy density and thermal stability of these batteries. Cobalt is also utilized in the manufacture of integrated circuits, multi-layer ceramic capacitors, and magnetic recording media.

However, cobalt's most extensive use is in superalloys and permanent magnets. Cobalt-based superalloys maintain strength at high temperatures and are used to make turbine blades for jet engines. Cobalt is a vital part of neodymium-iron-boron (NdFeB) permanent magnets which are essential in motors, generators, sensors, and MRI machines. In these applications, cobalt enables strong magnetic properties and high Curie temperatures. Overall, cobalt's high melting point, magnetism, and ability to enhance material properties make it indispensable for modern electronics.