Chelating agents role on phase formation and surface morphology of single orthorhombic YMn_2O_5 nanorods via modified polyacrylamide gel route

YMn2O5nanorods were synthesized through a modified polyacrylamide gel route.The synthesis strategy in this work is based on a sol-gel process using a polyacrylamide gel method in which oxalic acid,citric acid or tartaric acid is employed as the chelating agent.In the gel routes,oxalic acid was used as a carboxyl chelating agent,while citric acid or tartaric acid was a carboxyl and hydroxyl chelating agent.The as-prepared samples were characterized by means of techniques such as X-ray powder diffraction（XRD）measurement,thermogravimetric analysis（TG）,differential scanning calorimetry analysis（DSC）,Fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）,thermal expansion measurement and field-emission scanning electron microscopy（SEM）investigations.It was found that oxalic acid is the best chelating agent with Y（NO3）3·6H2O and Mn（CH3COO）2·4H2O as precursors to prepare a single orthorhombic YMn2O5nanorods at 1000°C.Scanning electron microscope observation shows that the morphology of YMn2O5powders is significantly dependent on the chelating agent.The peaks（single orthorhombic YMn2O5nanorods）at 642,600,573,546,521,493,486,468,448 and 400cm？1were observed from FTIR spectra.The phase,surface morphology and chelation mechanisms of YMn2O5samples have been discussed on the basis of the experimental results.