Synthesis of Sn1−x NixO2 nanoparticles: Observation of room temperature structural, optical and magnetic behavior

Abstract

Ni-doped SnO2 (Sn1−xNixO, x = 0.03, 0.05, 0.10, 0.12, and 0.15) powder samples were synthesized in a chemical auto combustion method and followed by calcination at 850 ºC for 5 h. Initially, their structural characteristics were investigated through X-ray diffraction (XRD) which reveals that the prepared samples are nanocrystalline rutile tetragonal structure similar to host SnO2. The surface morphological image analyses were done by scanning electron microscopy (SEM) which revealed the spherical nature of grains along with the presence of voids. From Raman spectroscopy study, the presence of fundamental vibration modes of SnO2 like A1g modes at 634 cm−1, B2g modes at 773 cm−1 and Eg modes at 473 cm−1 along with the formation of defects i.e. oxygen vacancies in the sample have been confirmed. Similarly, Fourier transforms infrared spectroscopy (FTIR) shows the prominent peaks of Sn-O and Sn-O-Sn vibrations around 560 cm−1and 615 cm−1 respectively, and confirms the incorporation of Ni ions into pure SnO2 lattice by the small shifting in the positions of the peaks. Furthermore, from UV–visible spectroscopy, the decrease of bandgap with increasing Ni concentration has been noticed. The existence of room temperature ferromagnetism in Ni-doped SnO2 nanoparticles has been confirmed from the hysteresis loop of the vibrating sample magnetometer measurement (VSM) measurement. From all the above characterizations, it has been confirmed that up to x = 0.12 of Ni has been incorporated into host material SnO2.