Strong nonlinear current–voltage behaviour in iron oxyborate

Strong nonlinear resistance has been found in the charge ordered ferroelectric iron oxyborate (Fe2OBO3) with a high dielectric constant and giant converse magnetoelectric effect. In low temperature range the I-V nonlinearity increases quickly with decreasing temperature. Transport measurements on polycrystalline and single crystal Fe2OBO3 indicate that the nonlinearity is not induced by grain boundaries. The nonlinear I-V behavior is intrinsically correlated with the charge order phase melting in Fe2OBO3 by detailed in-situ TEM investigations. These results provide an insight into structure-activity relationship of resistance switching effects at atomic and electric scales, which is essential for its potential application as varistors and storage media.