Study On Synthesis Of One-dimensional Nanomaterials Of Strontium Titanate And Barium Strontium Titanate

Strontium titanate is a kind of important electronic ceramic materials because of its excellent physics and chemical properties, which have been applicated in many fields. Owing to the need of nanotechnology and modern electronic industry, the synthesis methods maybe control the morphology and size of strontium titanate have started to attract the investigator's attention. One-dimensional nanomaterial has novel physical and chemical properties because of its anisotropy in one dimension, which would meet the need of apparatus intelligentization and miniaturization. Many methods have been utilized to synthesize one-dimensional nanomaterial. Among of these methods, the template method such as reverse microemulsion and sol-gel template can effectively control the morphology and size of product has attracted the investigator's attention. Using reverse microemulsion solution and porous anodic alumina film as templates in this text, we synthesized one-dimensional nanomaterials of strontium titanate and barium strontium titanate, and simultaneously studied the effect of the relevant reaction condition on the morphology and size of the products.In the second chapter of this text, SrTiO₃ nanorods were synthesized in cetyl trimethyl ammonium (CTAB) reverse microemulsion containing CTAB, n-hexanol, n-octane and water with Sr(OH)2 as reactants. The effects of different conditions such asω0[ω0 = n( H2O)/n(CTAB)], aging time and concentration of the reactants on the formation of the nanorods were studied, and a possible formation process of the nanorods was studied. Transmission electron microscope, electron diffraction and X-ray diffraction were used to characterize the morphology and structure of the synthesized nanorods. The results show that strontium titanate single crystal nanorods with a length of 260²000 nm and a diameter of 50¹00 nm are cubic phase. The molar ratio of Sr to Ti of the products is 1.0 by inductively coupled plasmas measurements.In the third chapter, a simple ternary phase diagram of cyclohexane/TX-100 and n-hexanol/distilled water microemulsion system was recorded, and then the barium strontium titanate nanorods were synthesized in quaternary water/oil microemulsion solution containing Triton X-100, cyclohexane, n-hexanol and water with Ba(OH)2 and Sr(OH)2 as reactants. The effects of different conditions such asω0 (molar ratio of water to surfactant), reactant concentration and aging time on the morphology and size of the products were studied. The obtained products were characterized by transmission electron microscope, select area electron diffraction, scanning electron microscope, energy disperse spectrum and X-ray diffraction techniques. The results show that the prepared barium strontium titanate nanorods belonging to cubic phase are a single crystal structure with a length of 500¹200 nm and a diameter of 50¹20 nm. The molar ratio of barium, strontium and titanate of the products is about 0.7:0.3:1.In the fourth chapter, we effectively fabricated the porous anodic alumina template, in which the depth and diameter of the pores is 11μm and 70 nm respectively, by a two-step anodizing process carried out under constant voltages of 40 V in 0.5 mol·L-1 oxalic acid solution at 15℃. The SrTiO₃ nanowires with length up to several microns are synthesized by porous anodic alumina template method connected with sol-gel process.