High Field ESR of<i>Kagome</i>Antiferromagnets SrCr_<i>x</i>Ga_{<b>12-<i>x</i></b>}O_<b>19</b>

Abstract

High field ESR of Kagome antiferromagnets SrCr x Ga 12- x O 19 have been observed in the submillimeter wave region from 1.8 K to 265 K. The concentration dependence was observed from x =0.6 to x =8.78, and all samples showed the decrease of the resonance field and broadening of linewidth as the temperature was decreased. As the linewidth is very broad at low temperature, for instance about 7 T at 4.2 K, the measurement using high frequency was essential. The results are discussed in connection with the peculiar magnetic behaviors of the system observed by other measurements.