Peat
char samples produ
ced by heat treatments under inert atmosphere were
chara
cterizedthrough
13C solid-state NMR, Mössbauer spe
ctros
copy, and magnetization measurements. Forsamples prepared above 700
C a set of strong spinning sidebands (SSB) were dete
cted in NMRspe
ctra a
cquired with dire
ct polarization (DP) and magi
c-angle spinning (MAS), an effe
ct thatwas shown to be
consequen
ce of the presen
ce of ferromagneti
c impurities asso
ciated with themineral
content of the studied peat samples. A detailed investigation on the nature and thermaltransformations of the magneti
c parti
cles present in the natural and heat-treated peat sampleswas
carried out by using magnetization measurements and Mössbauer spe
ctros
copy. A pronoun
cedin
crease in the ferromagneti
c chara
cter of the heat-treated samples was verified from 600
Cupward, with the development of Fe
3+ compounds, Fe
3C, and Fe
clusters. The effe
ct of theseferromagneti
c in
clusions was the
creation of magneti
c field inhomogeneities throughout thesample, whi
ch lead to the produ
ction of an anisotropi
c broadening of the NMR lines. A simplifiedmodel is presented to explain the influen
ce of these parti
cles on the
13C DP-MAS NMR spe
ctraof the heat-treated peat samples, showing their
capability to generate SSB mu
ch stronger thanthe ordinary SSB due to
chemi
cal shift anisotropy in pure
carbon materials.