At room temperature, Ba1-xCaxMoO4 polycrystalline solid solution thin films were prepared directly in contained Ca2+ and Ba2+ alkaline solution by electrochemical anode oxidation method. The crystal phase structure, s...At room temperature, Ba1-xCaxMoO4 polycrystalline solid solution thin films were prepared directly in contained Ca2+ and Ba2+ alkaline solution by electrochemical anode oxidation method. The crystal phase structure, surface morphology, ratio of compositions and room temperature fluorescence properties of the as-grown films were measured by using XRD, SEM, EDAX and Fluorescence Analysis techniques, respectively. The results reveal that the ratio of composition of Ba1-xCaxMoO4 films can be modulated by controlling the ratio of Ca2+ and Ba2+ in starting solutions; moreover it has important influence of ratio of composition of the films on the grain growth, the crystal lattice constant, the surface morphology as well as the fluorescence properties of the as-grown films.展开更多
Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an exce...Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an excellent NLO cryst al for UV region,while the high temperature one (α BBO) is known as a good bir efringent material.α BBO crystal possesses better transparency in the ultravio let region compared with commonly used YVO 4 and CaCO 3 crystals.However,due t o phase transition problem,it is difficult to grow single α BBO crystals by D CZ method,which restricts its wider application.α BBO crystal usually cracks upon cooling resulted from phase transition to β phase.Therefore,it is difficult to grow β BBO single crystals directly from pure BaB 2O 4 mel t;however,to grow single crystals of α BBO is not easy,either. Our recent experiments showed that one could avoid cracking of α BBO cryst als by Sr 2+ doping.This minute amount of Sr 2+ plays the role of structure stabilizer,which inhibits structural reconstruction. In this way,Sr 2+ d op ed BBO single crystals do not subject to phase transition from 925℃ down to roo m temperature. We have mow successfully grown out α BBO single crystals 30mm in diameter by D CZ method from Sr x Ba 1- x BO 4 melt with Sr concentration 0.3 0 .5%.The ratation rate is 10 15r/min,pulling speed is 1 2mm/h.Preliminary tests revealed that its structure and physic chemical properties were almost identic al to those grown from pure melts.These Sr 2+ doped α BBO crystals are no w being widely used in optical isolators.展开更多
文摘At room temperature, Ba1-xCaxMoO4 polycrystalline solid solution thin films were prepared directly in contained Ca2+ and Ba2+ alkaline solution by electrochemical anode oxidation method. The crystal phase structure, surface morphology, ratio of compositions and room temperature fluorescence properties of the as-grown films were measured by using XRD, SEM, EDAX and Fluorescence Analysis techniques, respectively. The results reveal that the ratio of composition of Ba1-xCaxMoO4 films can be modulated by controlling the ratio of Ca2+ and Ba2+ in starting solutions; moreover it has important influence of ratio of composition of the films on the grain growth, the crystal lattice constant, the surface morphology as well as the fluorescence properties of the as-grown films.
文摘Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an excellent NLO cryst al for UV region,while the high temperature one (α BBO) is known as a good bir efringent material.α BBO crystal possesses better transparency in the ultravio let region compared with commonly used YVO 4 and CaCO 3 crystals.However,due t o phase transition problem,it is difficult to grow single α BBO crystals by D CZ method,which restricts its wider application.α BBO crystal usually cracks upon cooling resulted from phase transition to β phase.Therefore,it is difficult to grow β BBO single crystals directly from pure BaB 2O 4 mel t;however,to grow single crystals of α BBO is not easy,either. Our recent experiments showed that one could avoid cracking of α BBO cryst als by Sr 2+ doping.This minute amount of Sr 2+ plays the role of structure stabilizer,which inhibits structural reconstruction. In this way,Sr 2+ d op ed BBO single crystals do not subject to phase transition from 925℃ down to roo m temperature. We have mow successfully grown out α BBO single crystals 30mm in diameter by D CZ method from Sr x Ba 1- x BO 4 melt with Sr concentration 0.3 0 .5%.The ratation rate is 10 15r/min,pulling speed is 1 2mm/h.Preliminary tests revealed that its structure and physic chemical properties were almost identic al to those grown from pure melts.These Sr 2+ doped α BBO crystals are no w being widely used in optical isolators.
