2076. LE CLERC, G., AND MICHEL, A. [Mineral Chemistry – Preparation and Properties of the Hexagonal Form of Nickel.] Compt. rend., vol. 208, 1939, pp. 1583-1585; Chem. Abs., vol. 33, 1939, p. 5252. Cubic Ni (I) heated at 170° for several days in CO is converted into the nonmagnetic variety (II). Thermomagnetic analysis of (II) shows a sudden appearance of magnetization at 250° with Curie point at 358°, and on cooling a further increase is shown. X-rays show (II) to be hexagonal with a=2.65 Å., c=4.32 (abs. 340), and the recovery of magnetization to be accompanied by reversion to the cubic form (I). This change is accompanied by a linear contraction of 5.4% (compared with 5.6% calculated). |