Tungsten arsenide

Tungsten Arsenide, WAs2.—When tungsten and arsenic are... 

In Moroccan deposits, cobalt occurs with nickel in the forms of smaltite, skuttemdite, and safflorite. In Canadian deposits, cobalt occurs with silver and bismuth. Smaltite, cobaltite, erythrite, safflorite, linnaeite, and skuttemdite have been identified as occurring in these deposits. AustraUan deposits are associated with nickel, copper, manganese, silver, bismuth, chromium, and tungsten. In these reserves, cobalt occurs as sulfides, arsenides, and oxides. 

Instead of glowbars, as used in MIR, tungsten halogen lamps are the sources of light. The detectors are solid-state semiconductors such as lead sulfide (PbS) or indium gallium arsenide (InGaAs). These are orders of magnitude quieter than typical MIR detectors and often more sensitive. 

Owing to the fact that valence electrons determine bonds, the electrical properties of a material are related to the bond type. In conductors such as metals, alloys, and intermetallics, the atoms are bound to each other primarily by metallic bonds, and metals such as tungsten or aluminum are good conductors of electrons or heat. Covalent bonds occur in insulators such as diamond and silicon carbide and in semiconductors such as silicon or gallium arsenide. Complexes and salts have ions that are bound with electrostatic forces. Ionic conductors can be used as solid electrolytes for fuel cells because solids with ionic bonds may have mobile ions. Most polymers have covalent bonds in their chains but the mechanical... 

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