Block (periodic table) elements that are commonly recognized as metalloids are in the p-block: boron, silicon, germanium, arsenic, antimony, and tellurium. Metalloids tend to have lower electrical conductivity than metals, yet often higher than nonmetals. They tend to form chemical bonds similarly to nonmetals, but may dissolve in metallic alloys without covalent or ionic bonding. Metalloid additives can improve properties of metallic alloys, sometimes paradoxically to their own apparent properties. Some may give a better electrical conductivity, higher corrosion resistance, ductility, or fluidity in molten state, etc. to the alloy. Boron has many carbon-like properties, but is very rare. It has many uses,
Application of silicon-germanium thermoelectrics in space exploration power applications. Application of silicon-germanium thermoelectrics in space exploration Silicon-germanium (SiGe) thermoelectrics have been used for converting heat into power in spacecraft designed for deep-space NASA missions since 1976. This material is used in the radioisotope thermoelectric generators (RTGs) that power "Voyager 1", "Voyager 2", "Galileo", "Ulysses", "Cassini", and "New Horizons" spacecraft. SiGe thermoelectric material converts enough radiated heat into electrical power to fully meet the power demands of each spacecraft. The properties of the material and the remaining components of the RTG contribute towards the efficiency of this thermoelectric conversion. Heavily doped semiconductors, such as silicon-germanium (SiGe) thermoelectric couples