Abstract
Thin whisker crystals of nickel, cobalt and silver can be mass-produced by the reduction of a molten mixture consisting of a starting halide and a secondary halide which are permeated in an absorbent powder. Many halides such as alkali halides can be used as the secondary halide. Carbonaceous powder can be used as the absorbent, but in the case of nickel, activated alumina powder is also effective. The chief roles of the secondary halide on the growth of nickel, cobalt and silver whiskers are to dissolve nickel halides, to lower the melting point of cobalt halides, and to wet the absorbent powder with AgI melt respectively. The properties of grown whiskers agree in general with those reported in the literature. All the cobalt whiskers, however, exhibit hcp structures when grown below 420°C.