Structural modifications of SnO2 due to the incorporation of Fe into the lattice

Abstract

Recently there is an increased interest in developing magnetic semiconductors due to their promising applications in spintronics. The semiconductors can be made ferromagnetic by doping with transition-metal ions. In this paper, the results of our studies using x-ray diffraction (XRD) and IR and Raman spectroscopic techniques on the effect of Fe doping on the structural properties of SnO2 are presented. The XRD results showed that the doping affects the structure and the lattice constants decrease as doping concentration increases, reaches a minimum, and again increases. The doped samples are under compressive strain and the strain is maximum for the sample doped with 3% (at. %) Fe. The grain size of the nanoparticles decreases from 42nm in undoped SnO2 to 26nm in Sn0.90Fe0.10O2. It was observed that the preferred orientation is along the (101) direction and both texture coefficient and preferential orientation show a dependence on doping level. The Raman spectra showed clear evidences of the change in grain size and incorporation of Fe into the crystal lattice. The Raman bands observed in the 700cm−1 region are assigned to the vibrational local modes of the Fe3+ ions which are occupying the sites of Sn4+ ions. The intensities of the Raman bands showed a strong dependence on the doping concentration. The decrease in intensity of the Sn–O symmetric stretching band at 630cm−1 for higher doping concentrations is explained to be due to the decrease in grain size. A striking correlation is found between the Fe Raman mode intensities and the ferromagnetic magnetization of Sn1−xFexO2, suggesting that the ferromagnetic behavior results from Fe3+ ions incorporated in the host SnO2 lattice.

Mössbauer study of Sn(Fe)O2 prepared by mechanosynthesis

“…The rutile lattice parameters were estimated to be a = 4.706 3Ǻ and c = 3.185 7Ǻ for all samples. The a value is lower than that corresponding to the rutile SnO 2 phase (a = 4.738 and c = 3.187Ǻ) and are in agreement with those reported for same composition samples prepared by chemical method [5]. This fact is related to the smaller Fe ions replacing Sn 4+ in the rutile phase.…”

Synthesis and field emission properties of SnO2 nanowalls

“…The sample resembles the vibration modes of microcrystal SnO 2 . There are three peaks at ~474, ~631 and ~775 cm −1 , which are consistent with the E g (translational), A 1g (symmetric Sn-O stretching) and B 2g (asymmetric Sn-O stretching) vibration modes of SnO 2 , respectively [13][14][15]. These peaks show that the SnO 2 nanowalls possess the main characteristic of the tetragonal rutile structure.…”

Structural and Optical Properties of Nanostructured Fe-Doped SnO2

“…On the other hand, the two modes of A 2g and B 1u are silent modes. The A 1g , B 1g , and B 2g modes arising due to the vibration of oxygen atom with the plane perpendicular to c axis, while E g is due to vibration in the direction of the c axis [25,26]. The Raman spectra of undoped and Fe-doped SnO 2 samples recorded in the frequency range 100-1000 cm −1 are presented in Fig.…”