“…Up to now, it has no exact answers, and even there are very few correlative literatures accessible yet. Just hierarchical core-shell and yolk-shell Fe 3 O 4 /CuSilicate composite microspheres for microwave absorption application have been reported, but the detailed absorption mechanism is missing [16,17]. Manganese dioxides (MnO 2 ) has been regarded as one of the most attractive microwave dielectric materials by reason of its low cost, environment friendly nature, strong dielectric loss and broad frequency bandwidth [18][19][20][21].…”