Soft structure of cubic leucite compounds having controlled the nano-space and its lower thermal expansion property

控制纳米空间的立方白榴石化合物的软结构及其较低的热膨胀性能

基本信息

批准号：
16560587
负责人：
KOBAYASHI Hidehiko
金额：
$ 2.44万
依托单位：
Saitama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2007
项目状态：
已结题

项目摘要

We chose a cubic pollucite, CsA1Si_2O_6, as a template compound, and report that the cubic Cs-leucite compounds with various chemical compositions can be synthesized by multi-step heating process as a solid-state reaction method, and that the thermal expansion properties in the range 298-1273K for all of the synthesized compounds were examined by using low- and high-temperature XRD.The results obtained can be summarized as follows. 1. Cubic cesium leucite-based compounds, Cs_<1-x> Al_<1-x>Si_<2+x> O_6 (x=0.0-0.25), Cs_<1-x> Na_xAlSi_2O_6 (x=0.1-0.25), Cs_<0.9-x> Na_xAl_<0.9> Si_2O_6 (x=0.1-0.25), and Cs_<0.9-x> Li_xAl_<0.9> Si_<2.1> O_6 (x=0.1,0.2), were synthesized using multistep heat treatment. Their crystal structures were cubic, with space group Ia-3d, in the range of 298-1273K. 2. The variation in unit cell volume with temperature for each composition was showed that Cs_<0.8> Al_<0.8> Si_<2.2> O_6 and Cs_<0.75> Al_<0.75> Si_<2.25> O_6 had significantly smaller degrees of lattice … More thermal expansion than CsAlSi_2O_6 and Cs_<0.9> Al_<0.9> Si_<2.1> O_6 CsAlSi_2O_6, Cs_<0.9> Al_<0.9> Si_<2.1> O_6, Cs_<0.8> Al_<0.8> Si_<2.2> O_6 and Cs_<0.75> Al_<0.75> Si_<2.25> O_6 showed linear coefficients of thermal expansion of 2.7×10^<-6>, 2.2×10^<-6>, 1.5×10^<-6> and 1.1×10^<-6> K^<-1>, respectively, which are attributed to an increase in not only space ratio but also Al/Si ratio in the framework in the unit cell. 3. Structural phase transition was accompanied by a significant decrease in the Cs content of compounds of the Cs_<1-x> Al_<1-x> Si_<2+x> O_6 series. Cs_<0.8> AL_<0.8> Si_<2.2> O_6 and C_<s0.75> A_<l0.75> Si_<2.25> O_6 were cubic at 123 K from the XRD patterns and did not undergo structural phase transition. 4. Cesium sodium leucites and cesium lithium leucites showed a lower thermal expansion than that of cesium leucites. In particular, the thermal expansion of Cs_<0.7> Na_<0.2> Al_<0.9> Si_<2.1> O_6 decreased to 0.14% at 1273K and that of Cs_<0.7> Li_<0.2> Al_<0.9> Si_<2.1> O_6 decreased to 0.081% at 1273K. 5. The lattice thermal expansion behavior of the synthesized cubic (Cs,Na)-pollucite compounds was investigated by high-temperature XRD analysis in the temperature range of RT-1173 K and was found to show a gradual decrease with decreasing Cs content of Cs_<1-x> Na_xAlSi_2O_6 and Cs_<0.9-x> Na_xAl_<0.9> Si_<2.1>O_6 series. 6. The lattice thermal expansion behavior of the synthesized cubic (Cs,Na)-Leucite compounds, Cs_<1.0> Na_xAl_<1+x> Si_<2-x>O_6 and Cs_<1-x> Na_xAlSi_2O_6 (x=0.1,0.2,0.3) was found to attribute to not only Al/Si ratio in the framework but also arrengements of Cs^ + ion and Na^+ ion in the unit cell. Less

我们选择一个立方粉粉CSA1SI_2O_6作为模板化合物，并报告具有各种化学疗法的立方CS-石蛋白化合物可以通过多步加热过程作为Asolid-State Reaction和热膨胀方法来合成各种化学物质。 298-1273K用于使用低温和高温的所有合成化合物。 0.0-0.25），cs_ <1-x> na_xalsi_2o_6（x = 0.1-0.25），cs_ <0.9-x> na_xal_ <0.9> si_2o_6）和cs_ <0.9-x> li_xal_ <0.9> li_xal_ 0.2）使用多步热处理，在298-1273k的范围内合成。 <0.75> si_ <2.25> O_6 Had Significantly Smaller DEGREES OF LATTICE… More Thermal Expansion Than CSALSI_2O_6 and CS_ <0.9> si_ <2.1> O_6 CSALSI_2O_6 8> Al_ <0.8> si_ <2.2 > O_6 and cs_ <0.75> al_ <0.75 > si_ <2.25> O_6显示了2.7×10^<-6>，2.2×10^<-6> 1.1×10^<-6> k^<-1>单元格的热膨胀的线性辅助因子。结构相变伴随着CS_ <1-x> al_ <2+x> o_6系列的CS含量显着降低。 XRD模式并未进行结构相变。 0.9> Si _ <2.1> O_6在RT-1173 K的温度范围内降低到0.081％。 Leucite化合物，CS_ <1.0> Na_xal_ <2-X> O_6和CS_ <1-X> Na_xalsi_2O_6（x = 0.1,0.2,0.3）不仅在ORK中，而且还能达到CS^ +的所有/si比离子和Na^ +离子较少