Crystal Structure, Lattice Strain, Morphology, and Electrical Properties of SnO₂ Nanoparticles Induced by Low Calcination Temperature

Abstract

The electrical properties of tin dioxide (SnO2) nanoparticles induced by low calcination temperature were systematically investigated for gas sensing applications. The precipitation method was used to prepare SnO2 powders, while the sol-gel method was adopted to prepare SnO2 thin films at different calcination temperatures. The characterization was done by X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The samples were perfectly matched with the rutile tetragonal structure. The average crystallite sizes of SnO2 powders were 45 ± 2, 50 ± 2, 62 ± 2, and 65 ± 2 nm at calcination temperatures of 300, 350, 400, and 450°C, respectively. SEM images and AFM topographies showed an increase in particle size and roughness with the rise in calcination temperature. The dielectric constant decreased with the increase in the frequency of the applied signals but increased on increasing calcination temperature. By using the UV-Vis spectrum, the direct energy bandgaps of SnO2 thin films were found as 4.85, 4.80, 4.75, and 4.10 eV for 300, 350, 400, and 450°C, respectively. Low calcination temperature as 300°C allows smaller crystallite sizes and lower dielectric constants but increases the surface roughness of SnO2, while lattice strain remains independent. Thus, low calcination temperatures of SnO2 are promising for electronic devices like gas sensors.

Effect of Thermal Treatment on the Phase Composition and Surface Properties of WO3‐TiO2 Nanocomposites Synthesized via Hydro‐Thermal Method

“…This increase in crystallite size is due to the growth of the crystals as a result of high calcination temperature. High calcination temperature provides sufficient kinetic energy for the migration of grain boundaries and small crystals fuse to form large sized particles [45,51] . These findings were also confirmed by FE‐SEM images which clearly show the formation of inter‐particle necks due to the coalescence of small crystals.…”

“…As the calcination temperature increases, the intensity of the peaks shows an increase, confirming increase in the crystallinity. The appearance of sharp and high intensity peaks indicates that the synthesized nanocomposite has high crystallinity [45–47] . Thus higher calcination temperature provides sufficient energy to form a highly crystalline form.…”

Tin Oxide Nanoparticles via Solar Vapor Deposition for Hexavalent Chromium Remediation

“…This finding matches with the XRD results and the fact that the SnO 2 crystallizes into polymorphs of cassiterite, the rutilelike type phase (of space group P4 2 /mnm), while the most stable form of SnO is the so-called litharge tetragonal crystal structure (P4/nmm). 32 In addition, it was previously found that, in general, tin oxides deposited at elevated partial pressures of oxygen consist of the rutile-like SnO 2 form, while low pressures of oxygen result in SnO. 33 Such morphological transformation may be attributed to oxygen vacancies due to partial deficiency of oxygen atoms, with reduction of some Sn 4+ ions to Sn 2+ as a possible charge compensation mechanism.…”

Role of grain alignment and oxide impurity in thermoelectric properties of textured n-type Bi–Te–Se alloy

“…It is suggested that there is a crystal growth after hot-press sintering. Further, the Scherrer-Gottingen formula is used to estimate the micro lattice strain of BTS (∼0.038) and Bi 6 O 7 (∼0.054) phases, presented in the hot-pressed pellet by choosing peaks at 27.82 • , 29.26 • , respectively [35]. The XRD patterns in both ⊥ to PA and || to PA look the same.…”