Fabrication and properties of C_60-involved mesoporous felloelectric ceramics

为了降低烧成温度以获得钙钛矿相，采用C&lt；60&gt；饱和甲苯溶液和由金属醇盐和醋酸铅制备的PZT溶胶，在PZT陶瓷中加入C_(60)作为填料进行了实验。在C&lt；60；溶解PZT；溶胶的制备过程中，发现在混合物中形成了细小的针状C&lt；60&gt；晶体。透射电子显微镜观察表明，针状晶须为直径小于1μm的单晶晶须，命名为“C&lt；60&>纳米晶须”。此外，还发现C_(60)纳米晶须是通过C_(60)饱和甲苯和异丙醇的液-液界面形成的，即“液-液界面沉淀法”。C；60；纳米晶须具有很强的柔韧性，可以弯曲成小于30μm的曲率半径。随着d…的减小，C&lt；60&>晶须的电阻率降低通过在碘溶解的异丙醇溶液和甲苯之间形成界面，可以得到更多的碘离子掺杂的C&lt；60&gt；晶须。掺碘的C&lt；60&gt；晶须表现出非线性的I-V曲线，而纯的C&lt；60&gt；晶须表现出线性的I-V曲线。利用原子力显微镜(AFM)针尖，可以在纳米晶须表面形成宽度为纳米级的凹槽。用液-液界面沉淀法成功地制备了C&lt；70和Gt；的纳米晶须。C&lt；70&gt；纳米晶须具有很好的结晶性，位错密度远低于C&lt；60&gt；纳米晶须。富勒烯(C_&lt；60&gt；和C_&lt；70&gt；)纳米晶须无一例外地是由平行于富勒烯分子紧密堆积方向的富勒烯分子组成。该工艺有望应用于具有有序介孔结构的PZT陶瓷。较少

An experiment was performed to incorporate C_<60> as a filler into leas zirconate titanate (PZT) ceramics by using a C_<60>-saturated toluene solution and a PZT sol prepared from metal alkoxides and lead acetate in order to lower the firing temperature to obtain perovskite phases. During the preparation of C_<60>-dissolved PZT sol, fine needle-like crystals of C_<60> were found to be formed in the mixture. Transmission electron microscopy observations showed that the needle-like crystals were single crystalline whiskers with a diameter less than 1 μm. These whiskers were named "C_<60> nanowhiskers". Further, the C_<60> nanowhiskers were found to be produced by forming a liquid-liquid interface of C_<60>-saturated toluene and isopropyl alcohol, I.e., "liquid-liquid interfacial precipitation method". The C_<60> nanowhiskers are very flexible and could be bent with a curvature radius less than 30 μm. The electrical resistivity of the C_<60> whiskers was found to decrease with decreasing d … More iameter, lodine-doped whiskers of C_<60> can be obtained by forming an interface between iodine-dissolved isopropyl alcohol solution and toluene as well. The iodine-doped C_<60> whiskers exhibited non-linear I-V curves, while the pure C_<60> whiskers showed linear I-V curves. Grooves with a width of nanometers could be prepared on the surface of a C_<60> nanowhisker by use of a AFM tip. Nanowhiskers of C_<70> have been successfully fabricated by the liquid-liquid interfacial precipitation method, too. The C_<70> nanowhiskers exhibit a very good crystallinity and a dislocation density much lower than the C_<60> nanowhiskers. The fullerence (C_<60> and C_<70>) nanowhiskers are composed of fullerene molecules that are aligned in parallel with the closed-packed direction of the fullerene molecules without exception.Titania thin films with a mesoporous structure have been successfully fabricated by using triblock copolymer P123. This process is expected to be applied to PZT ceramics with ordered mesoporous structure as well. Less