Tin Oxide Optical Research, Gas Sensor And Magnetic Properties

Tin oxide(SnO2), one of the most famous wide band gap semiconductor, bandwidth as length as3.6-3.8eV, tetragonal crystal system, rutile phase structure, application on many fields such as solar cells photoelectric conversion, for it have a good performance on optical, electrical, hold a very important place in semiconductor material industry. And, as more and more research on the room temperature ferromagnetic, both of doped with transition metal ions and pure SnO2, researcher pay more and more attention to it on spintronics fields.In this paper, we use two methods:hydrothermal method and sol-gel method, to manufacturing pure SnO2or doped with Mg (1%,3%,5%,7%,9%, and11%), film and nano power. We also made a lot of testing and analysis.Research on stannic oxide was departing for three parts:optical, gas detector, and room temperature ferromagnetic.We take some research like fluorescence spectrum, transmissivity and reflectivity, trough these test mainly can reflect the stannic oxide film or power’s transmission rate and radiation properties. We find that the samples which made by the hydrothermal method, there was very little difference between the transmission rate compared to the theoretical value. These maybe most come from the glass negatives. Its reflective was more than70%at the far-infrared region.Nowadays, research on stannic oxide about its gas sensing was very maturity, the nano stannic oxide which made by sol-gel method was very uniform in size. The average particle is about7.5nm, the largest particles smaller than10nm, the smallest is about7nm. Comparison of recent literature data, the results of the gas sensitive properties has been some progress:Sensitivity is48(literature data8-65), medium level, while the response time and recovery time of less than10seconds of data, the results should be better than the vast majority of literature into account, that samples we made, its gas sensitivity is prominent, have made some progress.Tested and analysis by XRD, EDS, pure SnO2crystal does not exist the impurity and the impurity ions, magnetic come from nano-materials’ surface oxygen vacancy defects, that is the intrinsic defect-induced magnetism.Doped sample Sn1-xMgxO2as rutile phase, the tetragonal symmetry, the lattice constant is slightly smaller than the pure of SnO2, magnetic is stronger than pure SnO2therefore the magnetic properties of the samples from two aspects:the ferromagnetic exchange coupling and surface oxygen vacancy defects.