We report the thickness dependence of critical current density （Jc） in YBa2Cu3O7-x （YBCO） films with BaZrO3 （BZO） and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using tri...We report the thickness dependence of critical current density （Jc） in YBa2Cu3O7-x （YBCO） films with BaZrO3 （BZO） and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. Comparing with pttre YBCO films, the Jc of BZO/Y2O3-doped YBCO films was significantly enhanced. It was also found that with the increase of the thickness of YBCO film from 0.25 μm to 1.5 μm, the Ic of BZO/Y2O3-doped YBCO film increased from 130 A/cm to 250 A/cm and yet Jc of YBCO film decreased from 6.5 MA/cm2 to 2.5 M A/cm2. The thick BZO/Y2O3-doped MOD-YBCO film showed lower Jc, which is mainly attributed to the formation of a-axis grains and pores.展开更多
Mg PSZ ceramics doped with Y 2O 3 and CeO 2 was prepared using traditional processing method. The fine grain PSZ ceramics( d c10 μm) sintered at low temperature(1550 ℃) was obtained by means of composition ...Mg PSZ ceramics doped with Y 2O 3 and CeO 2 was prepared using traditional processing method. The fine grain PSZ ceramics( d c10 μm) sintered at low temperature(1550 ℃) was obtained by means of composition design. The effects of co stabilization of Y 2O 3, CeO 2 and annealing at 1100 ℃ on material composition, microstructure and mechanical properties were studied. The results show that Y 2O 3 and CeO 2 during annealing at 1100 ℃ can inhibit subeutectoid decomposition reaction effectively, and optimize nucleation and growth of t ZrO 2 precipitates in c ZrO 2 matrix phase. The materials show transgranular and intergranular fracture characteristics, and exhibit better mechanical properties owing to the cooperative effect of stress induced transformation toughening and microcrack toughening.展开更多
Single crystals of huntite type double borates possess excellent physical and chemical properties and are applied in laser optics.Substituted with various rare earths and Ga 3+ ,Cr 3+ or Sc 3+ ions the properties of t...Single crystals of huntite type double borates possess excellent physical and chemical properties and are applied in laser optics.Substituted with various rare earths and Ga 3+ ,Cr 3+ or Sc 3+ ions the properties of these borates can be improved. [1] For the first time double borates RGa 3(BO 3) 4(R=Y 3+ ,Sm 3+ ,Eu 3+ ,Gd 3+ ,Tb 3+ and Dy 3+ )were synthesised by Blasse and Bril [2] at 750℃. The goal of the present work is to study the solid state reactions in the R 2O 3∶3Ga 2O 3∶4B 2O 3(R=La 3+ ,Y 3+ ,Ho 3+ ,Yb 3+ )systems.Such reactions can lead to RGa 3(BO 3) 4 formation. Reagent grade oxide powders were used as reactants and mixed together in desired rations in acetone.Then differential thermal analysis(DTA)was used to study the formations of borates and changes in structure of mixtures heated up to 1000℃.In addition pellets were prepared by using 15mPa pressure and sintered at different temperatures from 600℃ to 1100℃ for 20 hours in order to study the reactions by IR and X ray.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51272250)the National Basic Research Program of China(Grant No.2011CBA00105)+1 种基金the National High Technology Research and Development Program of China(Grant No.2014AA032702)the Beijing Natural Science Foundation,China(Grant No.2152035)
文摘We report the thickness dependence of critical current density （Jc） in YBa2Cu3O7-x （YBCO） films with BaZrO3 （BZO） and Y2O3 additions grown on single crystal LaAlO3 substrates by metalorganic deposition using trifluoroacetates （TFA-MOD）. Comparing with pttre YBCO films, the Jc of BZO/Y2O3-doped YBCO films was significantly enhanced. It was also found that with the increase of the thickness of YBCO film from 0.25 μm to 1.5 μm, the Ic of BZO/Y2O3-doped YBCO film increased from 130 A/cm to 250 A/cm and yet Jc of YBCO film decreased from 6.5 MA/cm2 to 2.5 M A/cm2. The thick BZO/Y2O3-doped MOD-YBCO film showed lower Jc, which is mainly attributed to the formation of a-axis grains and pores.
文摘Mg PSZ ceramics doped with Y 2O 3 and CeO 2 was prepared using traditional processing method. The fine grain PSZ ceramics( d c10 μm) sintered at low temperature(1550 ℃) was obtained by means of composition design. The effects of co stabilization of Y 2O 3, CeO 2 and annealing at 1100 ℃ on material composition, microstructure and mechanical properties were studied. The results show that Y 2O 3 and CeO 2 during annealing at 1100 ℃ can inhibit subeutectoid decomposition reaction effectively, and optimize nucleation and growth of t ZrO 2 precipitates in c ZrO 2 matrix phase. The materials show transgranular and intergranular fracture characteristics, and exhibit better mechanical properties owing to the cooperative effect of stress induced transformation toughening and microcrack toughening.
文摘Single crystals of huntite type double borates possess excellent physical and chemical properties and are applied in laser optics.Substituted with various rare earths and Ga 3+ ,Cr 3+ or Sc 3+ ions the properties of these borates can be improved. [1] For the first time double borates RGa 3(BO 3) 4(R=Y 3+ ,Sm 3+ ,Eu 3+ ,Gd 3+ ,Tb 3+ and Dy 3+ )were synthesised by Blasse and Bril [2] at 750℃. The goal of the present work is to study the solid state reactions in the R 2O 3∶3Ga 2O 3∶4B 2O 3(R=La 3+ ,Y 3+ ,Ho 3+ ,Yb 3+ )systems.Such reactions can lead to RGa 3(BO 3) 4 formation. Reagent grade oxide powders were used as reactants and mixed together in desired rations in acetone.Then differential thermal analysis(DTA)was used to study the formations of borates and changes in structure of mixtures heated up to 1000℃.In addition pellets were prepared by using 15mPa pressure and sintered at different temperatures from 600℃ to 1100℃ for 20 hours in order to study the reactions by IR and X ray.
