title: Nanocrystalline sensor-grade Sn1-xInxO2 (0 < or = x < or = 0.2).
abstract: Nanocrystalline Sn1-xInxO2 (0 < or = x < or = 0.2) has been successfully prepared by a solution chemical route. High-resolution transmission electron microscopy studies show that the average grain size of Sn0.8In0.2O2 heated at 310 degrees C, 500 degrees C, and 800 degrees C for 12 h is about 3-4 nm, 5-6 nm, and 7-10 nm, respectively. The corresponding values for pure SnO2 are 3-4 nm, 7-10 nm, and 50-90 nm, respectively. Powder X-ray diffraction and electron diffraction studies confirm the existence of solid solution only in the nanocrystalline state (the average particle size is in the range of 5-10 nm) with the solubility limited to 20% of In2O3. Indium ions stabilize the nanocrystalline nature of Sn1-xInxO2 (0 < or = x < or = 0.2) and prevent the grain growth by entering the SnO2 lattice. The thermal characteristics of nanocrystalline Sn1-xInxO2 (0 < or = x < or = 0.2) investigated by thermogravimetric (TG) and differential thermal analysis (DTA) show that the solid solution decomposes at 820 degrees C into SnO2 and In2O3, which is accompanied by a rapid crystal growth. The electrical conductivity and activation energy of Sn1-xInxO2 (0 < or = x < or = 0.2) undergo significant changes when the average grain size is less than or equal to 2 x the Debye length, LD.
authors.affiliation: Surface Science, Spectroscopy and Solid State Ionics Laboratory, Department of Physics, Southern University and A&M College, Baton Rouge, Louisiana 70813, USA.
authors.forename: K I
authors.initials: KI
authors.lastname: Gnanasekar
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: J C
authors.initials: JC
authors.lastname: Jiang
authors.forename: Deryn
authors.initials: D
authors.lastname: Chu
authors.forename: B
authors.initials: B
authors.lastname: Rambabu
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D007204:Indium / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods; D008854:Microscopy, Electron; D008863:Microspheres; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D009589:Nitrogen Oxides / Q000032:analysis; D010316:Particle Size; D012666:Semiconductors; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013696:Temperature; D017971:Tin Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D014159:Transducers; D014961:X-Ray Diffraction
chemical_list: D009589:Nitrogen Oxides; D017971:Tin Compounds; D007204:Indium; C045358:stannic oxide