Mössbauer and Raman characterization of ash produced by burning ancient buried Japanese cedar and investigation for its unusual color tone

Abstract

Mössbauer and Raman spectroscopic characterization of colored ash samples made by combustion of ancient buried Japanese cedar (Cryptomeria japonica) was carried out, and the factors governing the color tones were investigated mainly in terms of the chemical species of Fe. The ash samples displayed various unusual colors, depending clearly on the individual ancient tree and the part of it. Some of Mössbauer spectra of the ash samples showed magnetic hyperfine splittings due to internal magnetic fields. The Mössbauer and Raman spectra suggested that the primary Fe-containing species in all the ash samples was calcium ferrite, Ca2Fe2O5.

Unveiling the different physicochemical properties of M-doped β-NaFeO2 (where M = Ni or Cu) materials evaluated as CO2 sorbents: a combined experimental and theoretical analysis

“…It is worth noting that very few reports have studied the sodium ferrite structure through Raman spectroscopy. 11,54,55 Thus, the present investigation also helps to strengthen those previous findings. Typically, octahedrons in orthorhombic structures exhibit six vibrational modes ( ν 1 – ν 6 ), which arise from the octahedral Fe–O sites in the β-NaFeO 2 phase.…”