  Traces of superconductivity (SC) at elevated temperatures (up to 65 K) were
observed by magnetic measurements in three different inhomogeneous sulfur doped
amorphous carbon (a-C) systems: (a) in commercial and (b) synthesized powders
and (c) in a-C thin films. (a) Studies performed on commercial (a-C) powder
which contains 0.21% of sulfur, revealed traces of non-percolated
superconducting phases below Tc = 65 K. The SC volume fraction is enhanced by
the sulfur doping. (b) a-C powder obtained by pyrolytic decomposition of
sucrose did not show any sign for SC above 5 K. This powder was mixed with
sulfur and synthesized at 400 C (a-CS). The inhomogeneous products obtained,
show traces of SC phases at TC= 17 and 42 K. (c) Non-superconducting composite
a-C-W thin films were grown by electron-beam induced deposition. SC emerged at
Tc = 34.4 K only after heat treatment with sulfur. Other parts of the pyrolytic
a-CS powder, show unusual magnetic features. (i) Pronounced irreversible peaks
around 55-75 K appear in the first zero-field-cooled (ZFC) sweep only. Their
origin is not known. (ii) Unexpectedly these peaks are totally suppressed in
the second ZFC runs measured a few minutes later. (iii) Around the peak
position the field-cooled (FC) curves cross the ZFC plots (ZFC>FC). These
peculiar magnetic observations also ascribed to a-CS powder prepared from the
commercial a-C powder and are connected to each other. All SC and magnetic
phenomena observed are intrinsic properties of the sulfur doped a-C materials.
It is proposed that the a-CS systems behave similarly to well known high TC
curates and/or pnictides in which SC emerges from magnetic states.
