The Magnetic Anisotropy of Copper Sulphate Pentahydrate, CuSO4·5H2O, in Relation to Its Crystal Structure. Part I

Abstract

The magnetic anisotropy of the triclinic crystal CuS${\mathrm{O}}_4$·5${\mathrm{H}}_2$O has been measured. The crystal is found to be nearly uniaxial magnetically, i.e., has an axis of approximate magnetic symmetry, the susceptibility along the axis being less than that along perpendicular directions by about 300 × ${10}^{-6\mathrm{}}$ c.g.s. e.m.u. per gram molecule at 26°C. The above axis is inclined at 156°, 65°, and 52°, respectively, to the $a\text{'}$, $b\text{'}$ and $c\text{'}$ axes of the crystal. These results are discussed in relation to the known arrangement of the water molecules and oxygens round the ${\mathrm{Cu}}^{++}$ ions and the resulting crystalline electric fields acting on the latter.