Monocrystalline whiskers

The compound UPdln was first quoted to be a ferromagnet below 6 K (Troc 1986). Andreev and Bartashevich (1986) reported a much higher value Tc = 22 K and found fis = 0.15p.B/U. The most detailed study on UPdln was made by Briick et al. (1988). These authors studied the crystal structure the xac and Xdc behaviour, the magnetization in fields up to 35 T, C(T) in magnetic fields, and p(T) on polycrystalline materials and on monocrystalline whiskers grown along the hexagonal axis. 

Whiskers are normally obtained by vapour phase growth. They are monocrystalline, short fibres with extremely high strength because of their high aspect ratio (50 to 10 000). They have a diameter of a few microns, but they do not have uniform dimensions and properties. 

Classification of composites by the phase inclusion size bears a philosophical aspect how small should a component in the matrix be not to make the term composite material so universal as to include in fact all materials Interatomic distances in molecules and crystals are of 1.5 10 m dimensionality, distances between iterative elements of the crystalline structure are 10 —10 m, while the size of the smallest intermolecular voids in polymers is 10 m. Note that mean nanoparticle size (plastic pigments are 10-8-10 m in size, the diameter of monocrystalline fibers or whiskers is 10 —10 m, glass microspheres are 10 —10 m) is commensurate with parameters of monolithic simple materials. This means that in the totality of engineering materials, nanocomposites occupy a place at the boundary between composite and simple materials. 

A spontaneous columnar or cylindrical filament, which rarely branches, of monocrystalline tin emanating from the surface of a plating finish. Furthermore, tin whiskers may have the following characteristics ... 

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