High field ESR measurements of pyrochlore slab antiferromagnets Ba2Sn2Ga3+xZnCr7−xO22

High field ESR measurements of pyrochlore slab antiferromagnets Ba2Sn2Ga3+xZnCr7−xO22 have been performed in the millimeter wave region at temperatures from 4.2 to 200 K. The concentration dependence of Cr3+ ions was observed from x=0 to 5.0. For Ba2Sn2Ga3ZnCr7O22 (x=0), the pyrochlore slab is fully filled with Cr3+ ions, the line width of the ESR absorption lines increased and the resonance fields shifted as the temperature was decreased. These tendencies were suppressed as the Cr3+ concentration was decrease