Bentonite/Iron Oxide Composites: Preparation and Characterization by Hyperfine Methods
Figure 3
NMR spectra of 57Fe (gyromagnetic ratio 1.38 MHz/T) in maghemite phase measured at 4.2 K in zero external magnetic field. Gray spectral area marks superposed signals from 57Fe in A and B sites; left parts of the spectra belong to A sites, right part to B sites. (Black lines, the spectra evaluated from echoes 1–10 and normalized to equal areas; grey lines, spectra from echoes 1–21.) Maghemite signals of samples with = 600°C and 700°C were very weak due to negligible content of the phase; the latter spectrum is not shown.
