Semiconductors minerals, resistivity

The key technological goals include replacement of environmentally toxic metal coatings, deposition of new alloys and semiconductors and new coating methods for reactive metals. The main driving force for non-aqueous electrolytes has been the desire to deposit refractory metals such as Ti, Al and W. These metals are abundant and excellent for corrosion resistance. It is, however, the stability of their oxides that makes these metals difficult to extract from minerals and apply as surface coatings. 

Table 2 gives electrical, magnetic, and optical properties, while Tables 3 and 4 give more details on the semiconducting properties and band structures of the most common semiconductors. Table 5 lists semiconducting minerals with typical resistivity ranges. 

Chalcocite [22205-45-4] [Named from the Greek, chalkos, copper] (ICSD 100333 and PDF 33-490) Cu,S Ms 159.158 79.85 wt.% Cu 20.15 wt.%S (Sulfides and sulfosalts) Orthorhombic as 1188.1 pm bs 273.23 pm cs 1349.1 pm (Zs 96) Cuprite type Biaxial R = 32.2% 2.5-3 (HV 68-98) 5800 Habit massive, granular, euhedral crystals. Color black or iron black. Luster metallic. Diaphaneity opaque. Streak grayish black. Qea ige 110 indistinct. Twinning II0, 032, 112. Fracture Conchoidal. Occurrence secondary mineral in/near the oxidized zone of copper sultide ore deposits. Others p-type semiconductor with = 0.06 eV-0.13eV. Electrical resistivity 80 to 100 jQ.cm.> melting point of 1100 C... 

The semiconductor has been defined in several ways. Two of the most common definitions are based on the limits of two types of measurements (a) electrical resistance with values between 10 and 10 Q cm or 10 and 10 siemens/cm and (b) the energy gap with electronic excite energy between 0 and 3 electron volts (eV). However, some exceptions to these limits do occur. The best known material for the semiconductor is silicon (Si), but many others include naturally occurring minerals such as zinc blende (ZnS), cuprite (CU2O), and galena (PbS). 

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