Study of Growth and Photorefractive Anisotropy of Fe-Mn Codoped Lithium Niobate Crystal

Study of Growth and Photorefractive Anisotropy of Fe-Mn Codoped Lithium Niobate Crystal
　　The rare earth co-permeation were carried out on Kn [SiX3(OH2)3W9O37] (n=7 or 10 , X= Cu3+ , Fe3+ , Co3+, Mn2+, AI3+) with Keggin structure polyoxometalates (POMs) to prepare the KxLnyWO3 at 500℃, 550℃, 600℃, 650℃and 700℃. Moreover, the products were examined with XRD measurement. The result showed that the KxLnyWO3 has the tetrahedral symmetry. It was discussed that reactive temperature, permeating reagent and reactive Ball Neodymium Magnets time influence on prepared compounds and found the optimal method to prepare the rare earth tungsten bronze. 700℃,650℃,600℃,550℃and 4 hours are ideal for preparing the rare earth tungsten bronze by rare earth co-permeation with precursors of Kn [SiX3(OH2)3W9O37] respectively. There is no evidence that the formation of rare earth tungsten bronzes by rare earth reagents.The rare earth tungsten bronze were investigated by X-ray photoemission spectroscopy (XPS) and the result showed that the minimum Nd and La can permeate into the interface of the compounds and they are in formating of Nd+3 and La +3. There are two different W states that areW 6+ and W5+ while there is one O state. Moreover the thermal stabilities of the rare earth tungsten bronze were characterized http://www.chinamagnets.biz/ by TG-DTA. There are exothermic peaks at temperature of 300℃and temperature of 400℃, weight gain and weight loss in the TG curve respectively.The conductivity of the rare earth tungsten bronze has been measured with the electrode method. The result indicated that the conductivity of SiW9Cu3 after permeation in LaCl3 the value is 2.03 S·cm-1 and in CeCl3 the value is 0.0834 S·cm-1. The conductivity of tungsten bronze at different temperature was also determined and result showed that there are two processes. 更多还原