Multiphonon replicas in Raman spectra and conductivity properties of carbon films with different concentrations of sp1-bonds

Highlights: • Pulse-arc sputtering deposited carbon films resistivity increased with CH₄ addition. • Raman line corresponding to carbon chains increased with the film resistivity grows. • Sidebands of the carbon chains line observed and assigned to multiphonon replicas. -- Abstract: The method of ion-plasma pulse-arc sputtering of graphite in a methane atmosphere has been employed to produce carbon films with different rate of sp¹-bonds having a significant impact on the electrical conductivity of those films. Raman spectroscopy showed that the line near 2040 cm⁻¹, corresponding to the oscillation of long carbon chains with sp¹-hybridization, became more prominent with increase of methane concentration in the vacuum deposition chamber. The obtained spectra revealed multiphonon replicas of the 2040 cm⁻¹ line that is evidently associated with the presence of defects in carbon chains.