Journal Article 4 in. length single crystals atomically thin ε-Fe2O3 single crystals centimeter-sized films controllable Fe doping diatomite-templated synthesis full cell high electron mobility long cyclic stability monolayer Fe-MoS2 multiferroics room-temperature ferrimagnetism room-temperature ferroelectricity room-temperature magnetoelectric coupling single-atom cobalt-doped MoS2/carbon sodium-ion batteries transition-metal dichalcogenides ultralow contact resistance unidirectional domain orientation unidirectional domains zero energy barrier