Effect of Nd doping on structure, magnetic properties and microwave absorption performance of SrMnO3

A simple composite Sr 1– x Nd x MnO 3 ( x  = 0, 0.05, 0.1, 0.15, 0.2) nano powders were successfully prepared by the sol–gel method as a light-weight broadband electromagnetic wave absorber. The effect of Nd 3+ doping on the structure, microstructure and properties of SrMnO 3 was investigated. It is found that with the doping of Nd 3+ , the space group of the SrMnO 3 changes from p 63/ mmc to pm 3 m , and the crystalline shape starts to change from hexagonal to cubic crystalline. Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests confirm that the particle sizes of the sample decrease and the specific surface area increases, which are attributed to the inhibition of grain growth after Nd 3+ is doped. X-ray photoelectron spectroscopy (XPS) shows that after Nd 3+ doping, the content of oxygen vacancy increases, and Mn 4+ converts to Mn 3+ . Due to the defects of the materials, the polarization effect is enhanced, thus, the dielectric and magnetic properties of the doped samples are improved. The maximum reflection loss of the Sr 0.85 Nd 0.15 MnO 3 is −33.41 dB at 7.84 GHz for a thickness of 2.4 mm, while Sr 0.9 Nd 0.1 MnO 3 has the best bandwidth performance at 2.32 GHz with a reflection loss below −10 dB.