Effects of Sr2+ or Sm3+ doping on electromagnetic and microwave absorption performance of LaMnO3

The perovskite structure La1−xSr(or Sm)xMnO3±δ (x = 0, 0.25) powders were successfully fabricated by the traditional solid state reaction method. The influences of Sr2+ or Sm3+ doping on the static and dynamic magnetic performance were investigated. The resonance phenomena could be attributed to natural resonance and exchange resonance. The substitution of Sr2+ or Sm3+ into La3+ could greatly influence the resonance frequency. Furthermore, the microwave absorption performance of LaMnO3 was improved after the incorporation of Sr2+ or Sm3+. It is obtained that Sr2+ doped LaMnO3 had superior performance compared with that of Sm3+ doped LaMnO3. The maximum reflection loss was −30.0 dB at 13.968 GHz with a thickness of 1.6 mm. The microwave absorption performance was attributed to both the dielectric and magnetic losses.