Figure 4From: Magnesium Ferrite (MgFe2O4) Nanostructures Fabricated by ElectrospinningSEM micrographs of the MgFe2O4/PVP composite samples calcined in air at different temperatures for 2 h.a 500 °C,b 600 °C,c 700 °C, andd 800 °CBack to article page