Antimony electrical resistivity

Arsenic, antimony, and bismuth also exhibit a variety of allotropes. The most stable allotrope of arsenic is the gray (a) form, which is similar to the rhombohedral form of phosphorus. In the vapor phase, arsenic, like phosphorus, exists as tetrahedral AS4. Antimony and bismuth also have similar a forms. These three elements have a somewhat metallic appearance but are brittle and are only moderately good conductors. Arsenic, for example, is the best conductor in this group but has an electrical resistivity nearly 20 times as great as copper. 

The form of elemental antimony that is stable at normal temperatures and pressures is the gray, metallic rhombohedral a-form, mp 630.7 °C, bp 1587 °C, density 6.70 gcm. Crystals are lustrous. They have a relatively high electrical resistivity (41.7 1 2cm at 20°C). The structure of o -8b consists of sheets of covalently bonded antimony stacked in layers, which are formed of puckered slx-membered rings. Each antimony forms three shorter bonds (2.91 A) in the same layer as well as three longer bonds (3.36 A) to antimony atoms in the adjacent layer. In addition to the a-form, other allotropes include a very unstable yellow form and black forms obtained electrolytically or by condensing the vapor on cold surfaces. Two crystalline allotropes are made by high-pressure techniques. At 85 kbar, a modification with a primitive cubic lattice is formed where each antimony atom is in an octahedral environment of six equidistant (2.96 A) neighbors. Further... 

Antimony glance is best suited for the treatment. For each molecule of autimony trisulphide there should be present in the solution three molecules of sodium sulphide and after the extraction is complete the concentration should not exceed 12° Baumd (or 9° to 10°, if hot). To the electrolyte should be added 3 per cent, of common salt, which not only assists the clearing of the solution by the separation of dissolved sulphide of iron, but also reduces the electrical resistance of the solution. 

As evident from the data in Fig. 4.13, with time of battery operation, progressive corrosion of the positive grids increases their electrical resistance, which results in lower power and capacity performance. This process depends greatly on the content of antimony in the positive grids. 

Reasons for use abrasion resistance, cost reduction, electric conductivity (metal fibers, carbon fibers, carbon black), EMI shielding (metal and carbon fibers), electric resistivity (mica), flame retarding properties (aluminum hydroxide, antimony trioxide, magnesium hydroxide), impact resistance improvement (small particle size calcium carbonate), improvement of radiation stability (zeolite), increase of density, increase of flexural modulus, impact strength, and stiffness (talc), nucleating agent for bubble formation, permeability (mica), smoke suppression (magnesium hydroxide), thermal stabilization (calcium carbonate), wear resistance (aluminum oxide, silica carbide, wollastonite)... 

Specific fillers may be added to add or enhance specific properties in magnetic materials. Alumina, antimony trioxide or magnesium carbonate may be added to improve the flame retardant properties of the composite. The addition of lead oxide or carbide lead is suggested for improve resistance to nuclear radiation. To improve thermal conductivity, alumina, aluminium powder or silicates can be added. Silica, talc, mica or kaolin are indicated to increase the electrical resistance. The inclusion of metal powders, metal oxides or silicates are suggested to thermal absorption improvement. To increase the tensile strength in NR-based materials, carbon black in general, fibres or polymeric materials may be added. 

Until very recently, almost all PVC cables were stabilised with lead salts. These gave good thermal stability and electrical resistance, with low water absorption. When the cable was required to have better flame resistance than inherent in PVC, a small part of the calcium carbonate filler was replaced by antimony trioxide. All such cables perform well and have done for many years. Now, however, the need to focus on ecotoxicity has caused the lead salts to be replaced by a non-heavy metal system, usually a calcium-zinc complex. Likewise, the role of antimony is being questioned and formulators have come up with other solutions. 

Hard rubber Rubber Made by mixing natural rubber, rehydrated precipitated silica, and sulfur. This is then extraded and calendared, vulcanized under water, and dried. Finer pore diameter (0.2 pm average), relatively lower electrical resistance, excellent oxidation resistance, retards antimony transfer... 

Comparative Evaluation of the Traction Battery Separators Which separator properties are important for use in traction batteries For this aspect primarily the highly predominant application, namely forklift traction batteries, is to be considered chemical resistance against attacks by acid and oxidation, mechanical stability for problem-free assembly, stiffness to counteract overexpansion of the negative active material, and low acid displacement are particularly desirable. Delay in antimony poisoning, absence or near-absence of oily deposits in the cells, and - last but not least - a low electrical resistance complete the requirement profile. 

Lead is a bluish-white metal of bright luster, is very soft, highly malleable, ductile, and a poor conductor of electricity. It is very resistant to corrosion lead pipes bearing the insignia of Roman emperors, used as drains from the baths, are still in service. It is used in containers for corrosive liquids (such as sulfuric acid) and may be toughened by the addition of a small percentage of antimony or other metals. 

Solders. In spite of the wide use and development of solders for millennia, as of the mid-1990s most principal solders are lead- or tin-based alloys to which a small amount of silver, zinc, antimony, bismuth, and indium or a combination thereof are added. The principal criterion for choosing a certain solder is its melting characteristics, ie, soHdus and Hquidus temperatures and the temperature spread or pasty range between them. Other criteria are mechanical properties such as strength and creep resistance, physical properties such as electrical and thermal conductivity, and corrosion resistance. 

Silver is employed for low resistance electrical contacts and conductors, and in silver cell batteries. Antimony is used in lead add storage batteries to improve the workability of the lead and lead oxides. Copper and copper alloy wires, connectors, cables, switches, printed drcuit boards, and transistor and rectifier bases are common throughout the industry. Nickel is used in high resistance heating elements, glass-to-metal seals, batteries, and spedalty steels for power generation equipment Household appliances employ stainless and electroplated steel containing nickel. 

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