Effect of Mn Doping on the Structural, Optical and Magnetic Properties of SnO2 Nanoparticles

Undoped and Mn doped SnO2 prepared by co-precipitation method exhibits nanocrystalline nature with prominent peaks along (110), (101), (211), and (310) planes. All the prepared samples are nanocrystalline with crystallite size lying in the range of 4.8-5.6 nm. The prepared SnO2 nanopaxticles exhibit single tetragonal crystalline phase. The high resolution transmission electron microscopy images show that the particles are nanocrystalline in nature. The composition of the prepared samples have been analyzed using energy dispersive analysis of X-rays spectra. The photoluminescence spectroscopy shows the recombination of electrons in singly occupied oxygen vacancies with photoexcited holes in the valence band. Broad UV emission at 426 nm is observed in photoluminescence. UV vis absorption spectral studies showed a peak at 385 nm. Magnetic measurements revealed that all the doped samples exhibit room temperature ferromagnetism, which is identified as an intrinsic characteristic obtained on doping. Pure SnO2 nanopaxticles showed diamagnetism, SnO2 with lower Mn content show larger magnetization and with increasing Mn content the retentivity and coercivity are found to decrease.