340.    BREDIG, G., AND SCHWARZ VON BERGKAMPF, E.  [Hexagonal Nickel.]  Ztsch. Physik. Chem., Bodenstein-Festband, 1931, pp. 172-176; Chem. Abs., vol. 26, 1932, p. 14. 

                   Hexagonal Ni was prepared by the glow-discharge method of Bredig and Allolio in H₂.  With the Laue powder camera, a was found to equal 2.66 A. U., c=4.29 and c/a=1.61.  The theoretical value of c/a for hexagonal close packing is 1.63.  In N₂ a material was obtained in which a=2.60 A. U., c=4.15 and c/a=1.60.  The hexagonal Ni is nonmagnetic, but on heating to 300° it is transformed to magnetic Ni with a cubic lattice, in which a=3.52 sq. A. U.