Experimental Effects of R. F. Irradiation on N. M. R. Lines in Solids

Abstract In this paper measurements about the steady state of both Zeeman and dipolar energies of a spin system submitted to r. f. irradiation are presented. These experiments were performed in order to provide a quantitative check of the existing theories. Two samples are investigated, polycrystalline benzene in which relaxation is caused by molecular motions and a monocrystal of CaF 2 + 0.01% Ce +++ impurities. For both samples the regions of extreme narrowing and of large T 1Z /T 1D ratio are investigated. The results are discussed in terms of Provotorov's and Redfield's theories. While in the extreme narrowing region fairly good agreement is obtained some restriction to the Provotorov theory is observed in the region of long correlation times.