Hydrothermal synthesis and luminescent properties of BaBeF4: RE (RE = Eu, Tb)

The BaBeF4 powder has been hydrothermally synthesized from the double system. The effects of factors such as the ratio of initial reaction, pH value, reaction temperature and time were investigated. Moreover, the BaBeF4:RE (RE = Eu, Tb) phosphors were prepared by the hydrothermal method. Further, they were characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy and X-ray photoelectron spectroscopy. The luminescent properties were investigated by the luminescence spectrometer. The results show that the molar ratio and pH in the initial reaction mixture associated with the reaction temperature dominate the crystallization of the products. The products are air stable. XPS confirms the oxygen content of those products is very low. BaBeF4: RE obtained was pure phase of BaBeF4. It indicates that doping a low concentration of RE3+ ions could not change the structure. In the co-doped Eu3+ and Tb3+ system, Eu3+, Tb3+ and Eu3+ are observed in one matrix. These phenomena can be explained using an electron transfer theory. These RE ions occupy the sites of Ba2+ in BaBeF4. (c) 2005 Elsevier Inc. All rights reserved.