Magnetic fabrication

Hus J, Ech-Chakrouni S, JordanovaD (2002) Origin of magnetic fabric in bricks its implications in archaeomagnetism. Phys Chem Earth27 1319-1331. 

Noel, M, 1986, The palaeomagnetism and magnetic fabric of cave sediments from Pwll y Gwynt, South Wales, Phys. Earth Planet. Int. 44 62-71. 

We shall now briefly review a number of techniques that have been used in either factory or laboratory to prepare permanent magnets of the various suitable RE-TM compositions. They generally require that one or more alloys be prepared first in a separate step. It is therefore convenient to discuss alloy preparation and magnet fabrication methods separately and sequentially. 

Several striking examples demonstrating the atomically precise control exercised by the STM have been reported. A "quantum corral" of Fe atoms has been fabricated by placing 48 atoms in a circle on a flat Cu(lll) surface at 4K (Fig. 4) (94). Both STM (under ultrahigh vacuum) and atomic force microscopy (AFM, under ambient conditions) have been employed to fabricate nanoscale magnetic mounds of Fe, Co, Ni, and CoCr on metal and insulator substrates (95). The AFM has also been used to deposit organic material, such as octadecanethiol onto the surface of mica (96). New appHcations of this type of nanofabrication ate being reported at an ever-faster rate (97—99). 

Nickel normally crystallises in the f.c.c. structure it undergoes a magnetic transformation at 357°C and is ferromagnetic below that temperature. In all the alloys shown in Table 4.21 the f.c.c. (austenitic) structure is substantially retained, and in consequence most of the alloys possess the combination of properties required of materials for widespread industrial acceptability, i.e. tensile strength, ductility, impact strength, hardness, hot and cold workability, machinability and fabrication. 

Perhaps the most important polyester is polyethylene terephthalate), commonly known as PET (or PETE 1 on plastic beverage bottles). The annual production of PET in the United States is of the order of 108 kg (105 metric tons). Much of this is converted into fabric (trade name, Dacron) or magnetically coated film (Mylar). 

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