The ferroelectric-like behavior of ferric acetylacetone

The dielectric constant (ε) and the loss tangent (tan δ) of ferric acetylacetone Fe(ac.ac)3 as a function of temperature were studied. A peak value in both curves of ε and tan δ is obtained around 85°C. It has been explained as a transition temperature due to an internal structure reorientation at which the ferric acetylacetonate changed from ketonic to enolic complex. The X-ray diffraction studies show that the crystal structure of this compound is orthorhombic at room temperature. On heating the specimens to above 85°C, a minor change in the lattice parameters is recorded and the structure is characterized as pseudo orthorhombic. The effect of temperature on the resistivity is also studied and the curve shows a discontinuity near transition temperature.