Microwave absorption properties of Nd0.7Sr0.3MnO3 prepared using high-energy ball milling

► Metastable Nd0.7Sr0.3MnO3 was successfully prepared via high-energy ball milling. ► Microwave absorption of metastable state Nd0.7Sr0.3MnO3 was studied. ► The reflection loss of this material reaches -24dB with a thickness of 2.4mm. ► Microwave absorption is mainly due to the interfacial polarization. The permittivity and permeability behaviors of composites made from the high-energy ball milled Nd0.7Sr0.3MnO3 and paraffin wax have been studied in 2–20GHz. An optimal reflection loss of −24dB is reached at 16.4GHz with a matching thickness of 2.4mm. The excellent microwave absorption properties of the as-milled sample are attributed to the interfacial polarization of nanocrystal/amorphous phases and intrinsic electric dipole polarization, which enhance the dielectric losses. Permeability is found to have negative imaginary parts within 12–20GHz. The main contribution of the microwave absorption should result from the dielectric loss.