Electron paramagnetic resonance in Fe3O2BO3

We report an EPR study of the Fe oxyborate Fe3O2BO3 which shows charge ordering below 220 K, an antiferromagnetic transition at 112 K a nd weak ferromagnetism below 70 K. A single broad line ascribed to Fe2+ ions is observed in the temperature range 10-300 K with no anomalies at 112 and 70 K. However, for 120 < T < 180 K, discrete and reproducible spikes of very weak amplitude are superimposed on the EPR line. Possible interplay between the Wigner glass phase which appears between 112 and 220K and EPR results are discussed. <(c)> 2001 Elsevier Science B.V. All rights reserved.