The Bi 2Ti 2O 7 thin films have been prepared on silicon by metalorganic deco mposition (MOD) technique using bismuth nitrate and titanium butoxide as source materials.The growth procedure of the Bi 2Ti 2O 7 thin film...The Bi 2Ti 2O 7 thin films have been prepared on silicon by metalorganic deco mposition (MOD) technique using bismuth nitrate and titanium butoxide as source materials.The growth procedure of the Bi 2Ti 2O 7 thin films was discussed.Th e surface morphology of the Bi 2Ti 2O 7 film was studied by the Electri c Force Microscope (EFM).The crystallization of the films was studied by X r ay diffraction (XRD).The Bi 2Ti 2O 7 thin film prepared on (100) silicon subs trate was proved with strong (111) orientation.The dielectric properties and the current voltage (I V) characteristics were measured.The dielectric constant o f the Bi 2Ti 2O 7 thin films vs.temperature and frequency in the interval 100 8 00℃ were studied.The dielectric constang is 118 and dielectric loss is 0.07 res pectively at 100KHz at room temperature.The resistivity of the Bi 2Ti 2O 7 th in film is higher than 1×10 12 (Ω·cm) under the applied voltage from -5V to 5V.For films 0.4μm thick annealed at 580℃ for 40 minutes,their leakage cu r r ent density is 4.06×10 -7 A/cm 2 at an applied voltage of 15V.This shows the films have very good insulating property. We observed the obviously ferroelectric phase transition and its Curie temperatu re in the Bi 2Ti 2O 7 ceramic.Capacitance vs.temperature was measured with 27 800℃ at 1kHz,10kHz,100kHz and 1MHz,respectively.展开更多
Three-dimensional-ordered Yb/Er co-doped Bi2Ti207 inverse opal, powder, and disordered reference sam- ples are prepared and their upconversion （UC） emission properties and mechanisms are investigated. Sig- nificant ...Three-dimensional-ordered Yb/Er co-doped Bi2Ti207 inverse opal, powder, and disordered reference sam- ples are prepared and their upconversion （UC） emission properties and mechanisms are investigated. Sig- nificant suppression of UC emission is detected when the photonic band-gaps overlap with Er3＋ UC green emission bands. Interestingly, green and red UC emissions follow a two-photon process in the powder sample but a three-photon one in the inverse opal.展开更多
文摘The Bi 2Ti 2O 7 thin films have been prepared on silicon by metalorganic deco mposition (MOD) technique using bismuth nitrate and titanium butoxide as source materials.The growth procedure of the Bi 2Ti 2O 7 thin films was discussed.Th e surface morphology of the Bi 2Ti 2O 7 film was studied by the Electri c Force Microscope (EFM).The crystallization of the films was studied by X r ay diffraction (XRD).The Bi 2Ti 2O 7 thin film prepared on (100) silicon subs trate was proved with strong (111) orientation.The dielectric properties and the current voltage (I V) characteristics were measured.The dielectric constant o f the Bi 2Ti 2O 7 thin films vs.temperature and frequency in the interval 100 8 00℃ were studied.The dielectric constang is 118 and dielectric loss is 0.07 res pectively at 100KHz at room temperature.The resistivity of the Bi 2Ti 2O 7 th in film is higher than 1×10 12 (Ω·cm) under the applied voltage from -5V to 5V.For films 0.4μm thick annealed at 580℃ for 40 minutes,their leakage cu r r ent density is 4.06×10 -7 A/cm 2 at an applied voltage of 15V.This shows the films have very good insulating property. We observed the obviously ferroelectric phase transition and its Curie temperatu re in the Bi 2Ti 2O 7 ceramic.Capacitance vs.temperature was measured with 27 800℃ at 1kHz,10kHz,100kHz and 1MHz,respectively.
基金supported by the Natural Science Foundation of Yunnan Province(No.2010ZC038)the Open Foundation of Key Laboratory of Advanced Materialsin Rare,Precious and Non-ferrous Metals,Ministry of Education,and the Open Foundation of Key Laboratory of Advanced Materials of Yunnan Province(No.ZDS2010011B)
文摘Three-dimensional-ordered Yb/Er co-doped Bi2Ti207 inverse opal, powder, and disordered reference sam- ples are prepared and their upconversion （UC） emission properties and mechanisms are investigated. Sig- nificant suppression of UC emission is detected when the photonic band-gaps overlap with Er3＋ UC green emission bands. Interestingly, green and red UC emissions follow a two-photon process in the powder sample but a three-photon one in the inverse opal.
