Ttr 3 diffractometer

La(NO₃)₃·6H₂O and Co(NO₃)₂·6H₂O were dissolved in deionized water, followed by the addition of a mixture of citric acid and ethylene glycol. Subsequently, the obtained transparent solution was slowly evaporated to get a gel, which was decomposed at about 400 °C for 4 h to result in dark brown powders. The precursor powders were further annealed at 600, 700 and 800 °C for 6 h to produce LCO nanoparticles with different particle sizes, and at 1,000 °C for 12 h to the bulk sample. The phase purity and crystal structure of the samples were determined by X-ray diffraction at room temperature on a Rigaku TTR-III diffractometer using Cu K_a radiation (λ=1.5418 Å). The field emission SEM and TEM images were obtained on a JEOL-2010 SEM and a JEM-2100F TEM, respectively. The HRTEM images and the EELS analyses were performed on a JEOL JEM-ARM200F TEM/scanning TEM with a spherical aberration corrector. The magnetic measurements were carried out with a MPMS SQUID magnetometer. The nitrogen adsorption−desorption isotherms were conducted on a Micromeritics ASAP 2000 system at 77 K. X-ray photoelectron spectra were carried out on an ESCALAB 250 X-ray photonelectron spectrometer with Al Kα as the excitation source.

The crystal structures were investigated by powder X-Ray diffraction (XRD) on Rigaku TTR-III diffractometer with the Cu kα radiation (λ = 0.15418 nm) in the diffraction range of 2θ = 10–80°. The Raman spectra were recorded on a Reinshaw inVia Raman microscope with a power output of 3 mW under the laser excitation of 514 nm. The thermal decomposition analysis was determined on an American TA Q500 TGA thermal analyzer in air with a heating rate of 10 °C/min. The morphologies of the samples were observed by transmission electron microscopy (TEM, JEM-2100) with an accelerating voltage of 200 kV. To make a uniform dispersion of the products, the samples for TEM analysis were pretreated by dispersing it in absolute alcohol with a few seconds sonication and then dropped on a copper grid supported with amorphous carbon film.