Metalloid suggested that compounds of silicon, germanium, arsenic, and antimony with B metals, "are probably best classed as alloys". Among the lighter metalloids, alloys with transition metals are well-represented. Boron can form intermetallic compounds and alloys with such metals of the composition MB, if "n" > 2. Ferroboron (15% boron) is used to introduce boron into steel; nickel-boron alloys are ingredients in welding alloys and case hardening compositions for the engineering industry. Alloys of silicon with iron and with aluminium are widely used by the steel and automotive industries, respectively. Germanium forms many alloys, most importantly with the coinage metals. The
Boron arsenide Boron arsenide Boron arsenide is a chemical compound involving boron and arsenic, usually with a chemical formula BAs. Other boron arsenide compounds are known, such as the subarsenide BAs. Chemical synthesis of cubic BAs is very challenging and its single crystal forms usually have defects. BAs is a cubic (sphalerite) semiconductor in the III-V family with a lattice constant of 0.4777 nm and an indirect band gap of approximately 1.86 eV. It can be alloyed with gallium arsenide to produce ternary and quaternary semiconductors. Cubic BAs is reported to decompose to the subarsenide BAs at temperatures above 920 °C. Boron