Magnetodielectric effect and tunable dielectric properties of LaMn _1-xFe_xO₃

The dielectric properties of LaMn_1-xFe_xO₃ (LMFO, 0.10.5) under magnetic fields and electrical biases have been studied. A considerable low-field magnetodielectric (MD) effect is observed for x≤0.2, but it is suppressed by further Fe substitution. Besides the giant MD effect, the dielectric constants can also be tuned by dc electrical bias, and a reduction of more than 70% for x≤0.2 under a low bias of 40 V/cm is achieved. These results together with the impedance characteristics can be explained by the contributions of barrier layers at interfacial and grain boundaries as well as the magnetoelectric coupling. The giant dielectric response and tunability under both low magnetic and electric fields in the nonferroelectrics may be advantageous for applications.