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Perovskite LaFeO3 is one of the most useful materials for the application in a catalyst, gas sensors, and fuel cells, etc. LaFeO3 nanoparticles were synthesized by the citrate sol-gel method. According to the TG-DTA analysis on LaFeO3 xerogel powder, the proper crystallization temperature was found to be at 450 °C. The TEM images also show clear crystal formation was started at 450 °C. The LaFeO3 nanocrystalline particles were obtained by sintering the calcined powders at different temperatures (800 °C, 900 °C, and 1000 °C) for 4 hours. The resulting particles were characterized by XRD, EDXRF, FT IR, and SEM analysis. At 900 °C, the XRD pattern of LaFeO3 shows an orthorhombic crystal structure. The average crystallite sizes vary between 30-60 nm and the increase in crystallite size with increasing sintering temperatures and it may be due to the increase in grain growth. FT IR analysis shows strong La-O and Fe-O vibrations. Based on the XRD and FT IR data, the optimum sintering temperature was chosen at 900 °C. The SEM micrographs show that the morphology of LaFeO3 has small-sized grains with round shape. The optical properties were determined by UV-visible spectroscopy in the wavelength range of 300 nm-700 nm. The optical band gap energy values of LaFeO3 using Tauc’s plot were found to be about 2.45 eV. These results indicate that the LaFeO3 prepared by the sol-gel method has a relatively lower band gap value and so it can have the potential for photocatalytic applications.

Mineral oil, peanut oil and soybean oil were compared with water and gum arabic for their suitability as adhesives for seed inoculation with peat inoculants. Inoculated seeds were stored at 4, 28 and 34°C, and sampled after 1, 3 and 9 days to determine the survival of rhizobia. Germination and nodulation tests were performed on the inoculated seeds. Results showed that oils were suitable adhesives for peat inoculants. Although the oils initially bound less inoculant to the seed, the number of surviving rhizobia was similar to that obtained by the gum arabic treatment after storage at 28 and 34°C for 3 and 9 days. An interesting finding of this experiment was that peanut and soybean oils were superior to gum arabic in supporting significantly higher numbers of chickpea rhizobia at 34°C. Inoculated seeds tested for germination and nodulation showed no adverse effects from the oil treatments. Oils hold good potential as adhesives for seed application in inoculation technology.

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