The perovskite La1/3Sr2/3FeO3−δ was investigated by neutron diffraction, magnetic and Mössbauer spectroscopy measurements. La1/3Sr2/3FeO3−δ undergoes magnetic ordering at T = 190–200 K accompanied by charge disproportionation. Magnetic peaks due to charge ordering are observed below 200 K. The charge ordering is gradually developed below 200 K along with a charge disproportionation, 2Fe4+ ⇒ Fe3+ + Fe5+. La1/3Sr2/3FeO3−δ shows an antiferromagnetic structure at low temperature. Magnetic moments of about 3 and 1.3 μB were obtained from the neutron diffraction data refinement for Fe3+ and Fe5+ at 15 K, respectively, which suggest that both Fe ions are in a low spin state. These values are significantly lower than those reported by Battle et al for La1/3Sr2/3FeO2.98. Mössbauer spectra indicate that full charge ordering might be reached below 20 K with no Fe4+.

We report on the enhancement and possible control of both laser ignition and burn rates of Nitrocellulose (NC) microfilms when doped with graphene oxide (GO). A Nd:YAG (1064 nm, 20 ns) laser is used to ignite GO-doped NC films at low temperatures. The effect of GO on the doping concentration of the activation energies of laser ignition and thermal stability of the NC films is studied. The activation energy of laser ignition decreases with increasing GO/NC weight ratio and attains a constant value with higher concentrations. This behavior is accompanied by an increase in the thermal stability.

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