Probability of double exchange between Mn and Fe in LaMn_1−xFe_xO₃

The magnetism and transport properties of heavily doped perovskite LaMn_1−xFe_xO₃ (0.00⩽x⩽0.40) were studied. For the doped samples, there is a paramagnetic–ferromagnetic (PM–FM) transition both under zero field cooling and 0.01 Tesla field cooling condition but there is no insulator–metal transition. The curves are fitted well by the thermal activation model. The Mössbauer spectra of heavily doped samples demonstrate that the doped Fe ions are trivalent. In electron spin resonance spectra, many individual ferromagnetic resonance lines occur besides the normal paramagnetic resonance lines at T>T_C and then submerge in PM or FM lines at low temperature. We suggest that there is the probability of double exchange interaction between Fe³⁺ ions and Mn³⁺ ions in LaMn_1−xFe_xO₃.