PVA Battery Ni81Fe19 HiVacuum MeltingPoint LDPE Ni-FeAlloy Anneal SrTiO3 Pore neodymium_magnets polyvinyl acetate BismuthFerrite Calcite atomic_layer Polyurethane Polyaniline YszSubstrate ring shape HardDisk mechanical_property BTO TipBiasMode Titanate HBN Subhajjit PolycrystallineFerroelectricBCZT Copper molecule light_emitting plastics non_contact Butterfly MoirePattern membrane