Magnetic properties of ultrafine MnCo2O4 particles and their influence on sound absorption performance in graphene oxide/polyurethane foam

Abstract

We prepared ultrafine MnCo2O4 particles using a facile sol–gel autocombustion method. The structural and vibrational characterizations confirmed the formation of a pure cubic spinel phase in as-synthesized MnCo2O4 particles. The surface morphology analyses revealed the porous structure with an average particle size of 5 nm and uniform distribution of manganese (Mn), cobalt (Co), and oxygen (O) in the particles. We observed the presence of multiple valence states of Mn and Co, occupying both tetrahedral and octahedral sites, enhancing our insight into the material's electronic properties and structural configuration. Our magnetization studies unveiled a Curie Temperature (TC) of 185 K with ferrimagnetic ordering below TC, resulting in substantial magnetization (9.8 emu/g) and coercivity (3.46 kOe) at 2 K and weak magnetic behavior above TC. This is attributed to the finite size and surface effects. Furthermore, the incorporation of MnCo2O4 nanoparticles and graphene oxide into a polyurethane foam matrix resulted in an excellent sound absorption coefficient of 90 % at 2000 Hz. This outstanding acoustic performance underscores the versatile applications of MnCo2O4 nanoparticles in diverse noise mitigation applications. © 2024 Elsevier Ltd and Techna Group S.r.l.