Short Range Order Effect in Paramagnetic Resonance Line Width of CuF22H2O

A precies experimental study of the paramagnetic resonance line width in CuF 2 2H 2 O was made over a wide temperature range (1.1< T / T N <30). The result shows that the line width is isotropic at high temperatures but it becomes anisotropic below about 26°K. It was found that the temperature dependence of the paramagnetic resonance line width Δ H can be expressed by the following empirical formula: {aligned} H-[ H]∞{=}A'T/TN-1)⁻ⁿ, {aligned} where [ Δ H ] ∞ is the line width in the high temperature limit. A and n are the constants determined as follows: 1.1< T / T N <1.3