Theory of Some Magnetic Properties of Cobalt Tutton Salts

The g-values in the paramagnetic resonance experiment and the static magnetic susceptibilities of the cobalt Tutton salts are calculated under the assumption that the crystalline field is nearly cubic with a small tetragonal component. The values of these quantities depend on the value of a parameter η = 4δ/3λ, where δ is the energy separation between the lowest energy levels when the spin-orbit coupling is disregarded, and λ is the spin-orbit coupling constant. Comparing the theoretical results with the experimental data, we have estimated η = 3.5 ∼ 4.5 from g-values, η = 4 ∼ 5 from χ⊥, but the measured values of χ11 do not fall between the theoretical curves of χ11 versus T with η = 4 and 5. This discrepancy is discussed.