利用室温下弛豫铁电单晶0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3的材料参数,计算了[001]c极化PZN-7%PT晶体中的声表面波传播特性。结果表明,[001]c极化0.93Pb(Zn1/3Nb2/3)O3-0.07Pb TiO3单晶具有明显优于传统压电材料的声表面波特性。0.93Pb(Z...利用室温下弛豫铁电单晶0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3的材料参数,计算了[001]c极化PZN-7%PT晶体中的声表面波传播特性。结果表明,[001]c极化0.93Pb(Zn1/3Nb2/3)O3-0.07Pb TiO3单晶具有明显优于传统压电材料的声表面波特性。0.93Pb(Zn1/3Nb2/3)O3-0.07Pb Ti O3单晶的声表面波特性随着传播方向发生明显的变化。综合考虑晶体的三种声表面波特性,发现Y切型晶体的综合声表面波性能最好,声表面波机电耦合系数k2值较大,能流角和声表面波自由表面相速度值较小,有望应用于下一代低频声表面波设备中。展开更多
基于Swartz and Shrout的二次合成法,采用改进的两步法,将部分原料预合成,一次烧结合成具有100%钙钛矿结构的75Pb(Zn_(1/3)Nb_(2/3))O_3-10PbTiO_3-15BaTiO_3固溶体陶瓷。首先一次性称量PbO,然后和ZnNb_2O_6混合,在660～800℃预合成,将...基于Swartz and Shrout的二次合成法,采用改进的两步法,将部分原料预合成,一次烧结合成具有100%钙钛矿结构的75Pb(Zn_(1/3)Nb_(2/3))O_3-10PbTiO_3-15BaTiO_3固溶体陶瓷。首先一次性称量PbO,然后和ZnNb_2O_6混合,在660～800℃预合成,将预合成产物粉碎后再与TiO_2和BaCO_3按化学计量称量,充分混合后,在1060～1140℃保温1～2h烧结成陶瓷试样。实验结果表明:改进的两步法工艺能够将预合成温度降为660℃,烧结温度能被拓宽到80℃获得100%钙钛矿结构的固溶体陶瓷。不同于传统的预合成和烧结,改进的两步法工艺简单、有效,在预合成阶段没有形成钙钛矿相,烧结阶段陶瓷的成瓷和致密化同时进行,完成了中间相向钙钛矿相的转变,获得了介电性能优良的陶瓷试样。展开更多
The nickel‐based complex Ni‐CH3CH2NH2‐intercalated niobate layered perovskite Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was synthesized via a facile in situ chemical reaction method.Using ultrathin H1.78Sr0.78Bi0.22Nb2O7...The nickel‐based complex Ni‐CH3CH2NH2‐intercalated niobate layered perovskite Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was synthesized via a facile in situ chemical reaction method.Using ultrathin H1.78Sr0.78Bi0.22Nb2O7nanosheets and nickel acetate as precursors.The composition,structure,photophysical properties,and photocatalytic activity for H2production of Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7were studied systematically.The photocatalyst loaded with0.5wt%Ni exhibited the highest H2evolution rate of372.67μmo/h.This was0.54times higher than the activity of the H1.78Sr0.78Bi0.22Nb2O7nanosheets.The activity of the optimized Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was comparable to that of the Pt‐loaded sample under the same reaction conditions.The photocatalytic activity of the Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was mainly attributed to the excellent separation of photogenerated carriers,after formation of the intercalated complex Ni‐CH3CH2NH2.This study provides a facile strategy to synthesize a non‐precious metal‐loaded photocatalyst for H2production.展开更多
文摘利用室温下弛豫铁电单晶0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3的材料参数,计算了[001]c极化PZN-7%PT晶体中的声表面波传播特性。结果表明,[001]c极化0.93Pb(Zn1/3Nb2/3)O3-0.07Pb TiO3单晶具有明显优于传统压电材料的声表面波特性。0.93Pb(Zn1/3Nb2/3)O3-0.07Pb Ti O3单晶的声表面波特性随着传播方向发生明显的变化。综合考虑晶体的三种声表面波特性,发现Y切型晶体的综合声表面波性能最好,声表面波机电耦合系数k2值较大,能流角和声表面波自由表面相速度值较小,有望应用于下一代低频声表面波设备中。
文摘基于Swartz and Shrout的二次合成法,采用改进的两步法,将部分原料预合成,一次烧结合成具有100%钙钛矿结构的75Pb(Zn_(1/3)Nb_(2/3))O_3-10PbTiO_3-15BaTiO_3固溶体陶瓷。首先一次性称量PbO,然后和ZnNb_2O_6混合,在660～800℃预合成,将预合成产物粉碎后再与TiO_2和BaCO_3按化学计量称量,充分混合后,在1060～1140℃保温1～2h烧结成陶瓷试样。实验结果表明:改进的两步法工艺能够将预合成温度降为660℃,烧结温度能被拓宽到80℃获得100%钙钛矿结构的固溶体陶瓷。不同于传统的预合成和烧结,改进的两步法工艺简单、有效,在预合成阶段没有形成钙钛矿相,烧结阶段陶瓷的成瓷和致密化同时进行,完成了中间相向钙钛矿相的转变,获得了介电性能优良的陶瓷试样。
基金supported by the National Natural Science Foundation of China(U1403193,21643012)~~
文摘The nickel‐based complex Ni‐CH3CH2NH2‐intercalated niobate layered perovskite Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was synthesized via a facile in situ chemical reaction method.Using ultrathin H1.78Sr0.78Bi0.22Nb2O7nanosheets and nickel acetate as precursors.The composition,structure,photophysical properties,and photocatalytic activity for H2production of Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7were studied systematically.The photocatalyst loaded with0.5wt%Ni exhibited the highest H2evolution rate of372.67μmo/h.This was0.54times higher than the activity of the H1.78Sr0.78Bi0.22Nb2O7nanosheets.The activity of the optimized Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was comparable to that of the Pt‐loaded sample under the same reaction conditions.The photocatalytic activity of the Ni‐CH3CH2NH2/H1.78Sr0.78Bi0.22Nb2O7was mainly attributed to the excellent separation of photogenerated carriers,after formation of the intercalated complex Ni‐CH3CH2NH2.This study provides a facile strategy to synthesize a non‐precious metal‐loaded photocatalyst for H2production.
