High-resolution neutron study of the effects of magnetic dilution in the strongly frustrated system SrCrxGa12–xO19

We have pursued the neutron examination of SrCrxGa12–xO19, with special emphasis on the role of magnetic dilution in the spin dynamics and freezing. We have examined samples with different levels of magnetic dilution, ranging from 7.0 < x < 8.8, characterized by neutron powder diffraction with Rietveld refinements and bulk susceptibility. The elastic magnetic response examined by high-resolution neutron scattering ((mu)eV range) has confirmed the trend on increasing dilution: the decrease of the freezing temperature as well as of the frozen moment/magnetic site. However, the least diluted sample that we have produced with x=8.8, deviates from this trend, with a smaller than expected freezing temperature and frozen moment. This suggests that the freezing might be suppressed at the clean limit.