Physicochemical investigations of structurally enriched Sm3+ substituted SnO2 nanocrystals

The present study portrays structural, magnetic, electrical, optical and electronic characteristics of polycrystalline pristine and aliovalent Sm 3+ modified Tin oxide (SnO 2 ) nanocrystals [Sn (1− x ) Sm x O 2 nanocrystals, where x = 0, x = 0.05, and x = 0.10] were synthesized using conventional sol–gel route. X-ray diffractogram showed rutile-type tetragonal crystallinity [space group P4 2/ mnm] for all the samples. Microstructural investigations depicted well-interlinked grains and it was observed that average grain size increases with Sm 3+ substitution in the crystal framework of SnO 2 . HRTEM images also confirmed the tetragonal rutile symmetry for all the compositions. FTIR spectra validated the phase pure synthesis and formation of Sm 3+ substituted SnO 2 nanocrystals as bend at 470 cm −1 attributed to the Sn/Sm–O vibrations. Magnetic measurements depicted that Sm 3+ modified compositions showed room temperature magnetism with low coercivity and retentivity, while pristine SnO 2 nanocrystals illustrated diamagnetism at higher magnetic field and defect-assisted ferromagnetism at low fields. The maximum value of dielectric constant ( ε ′) was observed for pure SnO 2 , and dielectric constant ( ε ′) decreases with increasing Sm 3+ concentration. I-V curves showed non-linear behavior for all the samples and the maximum resistance was found for pure SnO 2 nanocrystals. The incorporation of aliovalent rare-earth Sm 3+ ion in SnO 2 crystal matrix induces ferromagnetism in the system, which makes it dilute magnetic semiconductor for magneto-or spin electronics.