Co-59 nuclear magnetic resonance in the metamagnetic system Y1-xGdxCo3

A detailed nuclear magnetic resonance (NMR) study of some intermetallic com pounds of the series Y1-xGdxCo3 is presented. These are results where the N MR lines corresponding to the four magnetic sites of these compounds appear clearly resolved in the NMR spectra. We found, however, that the number of lines and their widths are strongly dependent on the radio frequency (rf) power level, which may help to explain some of the discrepancies found in N MR literature on these compounds. From the dependence of the NMR spectra wi th rf power we concluded that the site labeled 18h presents the largest loc al magnetic anisotropy. No significant changes are observed in the value of the hyperfine fields at any site as a function of the Gd concentration, x. (C) 2000 American Institute of Physics. [S0021-8979(00)30008-1].