论文信息 - Anomalous paramagnetism of Ni2+ perchlorate hexahydrate at low temperatures

Anomalous paramagnetism of Ni2+ perchlorate hexahydrate at low temperatures

Nickel perchlorate hexahydrate Ni(ClO4)26H2O is found to undergo a new type of phase change from C2v7 to P21c/ symmetry as in the case of Fe(ClO4)26H2O. The mean susceptibility and the anisotropy of the crystal have been measured between 80K and 300K. An abrupt break in the mean moment square and anisotropy curves is observed at (225+or-1)K. The Mossbauer studies of this crystal diluted with Fe2+ ions showed anomalies in the ( Delta EQ) values at about 120K. Below Tc( approximately=225K) the ionic susceptibility Kperpendicular to becomes greater than K/sub /// and the trigonally distorted octahedron becomes tetragonally distorted. It is also found that on cooling through Tc, the value of the zero field splitting D changes sign and magnitude.

B. K. Chaudhuri

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