Per atom muon capture ratios and effects of molecular structure on muon capture by γ-Fe 2 O 3 and Fe 3 O 4

An elemental analysis method utilizing muons has been demonstrated to be effective for non-destructive and quantitative analysis of precious bulk materials. In muon capture process, molecular structure dependence was known, and this property has the potential to be used to identify chemical structure in addition to elemental composition. Before these potential applications, fundamental studies examining the muon capture process are necessary. In this study, muon capture ratios for two iron oxide compounds, which are both important in earth science, γ-Fe2O3 (maghemite) and Fe3O4 (magnetite), were measured. The measured muon capture ratios were A(Fe/O) = 2.34 ± 0.03 and A(Fe/O) = 2.77 ± 0.03 for γ-Fe2O3 and Fe3O4, respectively.