Optimizing energy storage and magnetoelectric performance through core–shell engineering: A study on Ni0.5Co0.5Fe2O4-BaTiO3 multiferroic composite materials

Abstract

In this report, we have synthesized Ni0.5Co0.5Fe2O4 (NCFO) and BaTiO3 (BTO) core–shell (12 % NCFO − 88 %BTO) multiferroic nanopowder by hydrothermal method and sol–gel method, respectively. The structural, morphological, ferroelectric, and magnetoelectric properties of the as- prepared sample was investigated in detail. X-ray diffraction results revealed that no secondary phase is obtained. As investigated from the scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis, the grains are almost spherical, which depicts the core–shell like morphology and the presence of all the constituent elements in the prepared sample. FTIR analysis gives information about the formation of two individual phases and the different chemical compositions present in the sample. The prepared core–shell composite exhibits a notable energy storage density W (38.25 mJ/cm3), accompanied by a slightly lower energy storage efficiency η (46.50 %) and energy loss density Wrec (17.78 mJ/cm3). Magnetic characterization revealed that the sample shows lower saturation magnetization (1.33 emu/g) with coercivity (430 Oe) and magneto-crystalline anisotropy (595.7 erg/g). A moderate magnetoelectric coefficient of 18.34 mV/cm*Oe is observed on the higher field side, surpassing the value on the lower field side 32.62 mV/cm*Oe. Anisotropy in the system leads to varying magnetoelectric coefficients in different directions. These findings provide valuable insights for enhancing the magnetoelectric response in core–shell multiferroic composites.