H. Kiriyama
Jul 1, 1962
Citations
0
Influential Citations
32
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The dielectric properties of single crystals of cupric formate tetrahydrate have been investigated over the range 30c./sec. to 10 Mc./sec. from the liquid nitrogen temperature to the dehydration point, 46°C. This crystal undergoes a phase transition at –36°C, indicated by a sudden change in the dielectric properties. Above the transition point, large dielectric dispersion and absorptions are present when the applied electric field is along the crystallographic a- and b-axes, whereas along the normal to (0 0 1) plane, the variations in permittivity and the loss factor with temperature and frequency are quite small. The results for the radio frequency absorption can be explained on the basis of a molecular mechanism involving the axial reorientation of two water dipoles in the formula unit of Cu(HCO2)2·4H2O. The energy barrier H(kcal./mol.) and the frequency factor A(sec−1) associated with the dipole orientation have been obtained as follows : along the a-axis A=1×1011, H=6.7; along the b-axis A=8×109, H=4....