Intrinsic susceptibility and bond defects in the novel two dimensional frustrated antiferromagnet Ba2Sn2ZnCr7pGa10-7pO22.

We present microscopic and macroscopic magnetic properties of the highly frustrated antiferromagnet Ba(2)Sn(2)ZnCr(7p)Ga(10-7p)O22, respectively, probed with NMR and SQUID experiments. The T variation of the intrinsic susceptibility of the Cr3+ frustrated Kagomé bilayer, chi(Kag), displays a maximum around 45 K. The dilution of the magnetic lattice has been studied in detail for 0.29</=p</=0.97. Novel dilution independent defects, likely related with magnetic bond disorder, are evidenced and discussed. We compare our results to SrCr(9p)Ga(12-9p)O19. Both bond defects and spin vacancies do not affect the average susceptibility of the Kagomé bilayers.