610305.fig.0041
Figure 41: Mössbauer spectra for pure Fe foil (a) and nanoparticles ((b)–(e)) of 𝐷 = 1 3 ± 2  nm size at different temperatures. (a) 293 K; (b) 293 K; (c) 80 K; (d) 4.2 K; (e) particles preliminarily aged at 80 K and subsequently warmed up to 293 K.