On The Plasmon-Assisted Detection Of A 1585cm(-1) Mode In The 532nm Raman Spectra Of Crystalline Alpha-Fe2o3/Polycrystalline Nio Core/Shell Nanofibers

Crystalline hematite/polycrystalline nickel oxide (alpha-Fe2O3/NiO) core/shell nanofibers are prepared by electrospinning and calcination, followed by a varying number (100-1150) of atomic layer deposition cycles of NiO. The deposition of the conformal NiO layer leads to the passivation of the surface states and the appearance of a photoluminescence band in the micro-Raman spectra excited by 532nm laser. As a continuous NiO layer is formed, a peak, possibly arising from a two-magnon mode, appears at 1585cm(-1). The detection of the peak, which is not observed in the spectra excited by a 633nm laser, is assisted by the surface plasmon at around 510nm introduced by the polycrystalline NiO layer, due to the electron doping induced by coordination-defects at its edge-rich surface. Published under an exclusive license by AIP Publishing.