Electrical transport and EPR properties of the α, β, and γ phases of Fe2WO6

The polymorphic modifications alpha, beta, and gamma Fe2WO6 of the iron (III) tungstate have been investigated by resistivity and electron paramagnetic resonance (EPR) measurements. The high-electrical resistivity for all phases complies with the dominant antiferromagnetic component of the compounds. The EPR spectra comprise a broad exchange narrowed EPR line due to Fe3+ ions. The broadening of the EPR linewidth is explained in terms of the critical spin fluctuations near the antiferromagnetic phase transition. The shift of the resonance field and the temperature dependence-of the EPR intensity imply an extended region of short-range order correlations. [S0163-1829(99)09535-1].