ELECTRON-SPIN ECHO AT S-BAND - NUCLEAR MODULATIONS AND DECAY IN C(60)POWDER

At S-band (approximately 3 GHz) the modulation amplitude of the Electr on Spin Echo patterns is increased with respect to the amplitude at X- band: as a consequence, it is possible to reveal the presence of nucle i not detectable at X-band. In this paper the results obtained by runn ing ESE experiments at S-band on a C60 powder sample containing radica ls are shown and discussed. The two- and three-pulse Electron Spin Ech o patterns exhibit both C-13 modulation and proton modulation not dete cted at X-band. The experimental data are quantitatively analyzed by s imulating the time-domain patterns and their Fourier transforms. It re sults that a noticeable amount of proton nuclei surrounds the intrinsi c paramagnetic centers. On the basis of the analysis, a possible expla nation of their existence is given.