排序方式: 共有63条查询结果,搜索用时 15 毫秒
11.
利用金刚石对顶砧(DAC)装置产生高压,在室温下、0~32 GPa压力范围,对天青石(SrSO4)进行了原位高压X射线衍射和拉曼光谱研究. 根据高压X射线衍射的数据,测定了天青石的等温状态方程,得到天青石的零压体弹模量KT0=83GPa(K'T0=4), 在所研究压力范围内没有观察到相变的发生. 高压拉曼光谱的数据显示,在5GPa左右,SO4四面体弯曲振动峰发生劈裂,这是由SO4四面体畸变引起的;同时,所有的拉曼振动峰都随着压力的增加而增加, 并且,高频模的平均压力导数要高于低频模的,根据以上数据获得了模格林奈森参数. 相似文献
12.
Raman and X-Ray Investigation of Pyrope Garnet (Mg0.76Fe0.14Ca0.10)3Al2Si3O12 under High Pressure 下载免费PDF全文
The compressional behavlour of natural pyrope garnet is investigated by using angle-dlspersive synchrotron radiation x-ray diffraction and Raman spectroscopy in a diamond anvil cell at room temperature. The pressureinduced phase transition does not occur under given pressure. The equation of state of pyrope garnet is determined under pressure up to 25.3 GPa. The bulk modulus KTO is 199 GPa, with its first pressure derivative K′TO fixed to 4. The Raman spectra of pyrope garnet are studied. A new Raman peak nearly at 743 cm^-1 is observed in a bending vibration of the SiO4 tetrahedra frequency range at pressure of about 28 GPa. We suggest that the new Raman peak results from the lattice distortion of the SiO4 tetrahedra. All the Raman frequencies continuously increase with the increasing pressure. The average pressure derivative of the high frequency modes (650-1000 cm^-1) is larger than that of the low frequency (smaller than 650 cm^-1). Based on these data, the mode Grǖneisen parameters for pyrope are obtained. 相似文献
13.
酞菁化合物LB单分子膜的SERRS 总被引:4,自引:0,他引:4
酞菁类化合物具有优良的光电特性,选择适当的取代侧链可得到稳定的LB成膜材料,可望在微电子器件等方面获得重要的应用.本工作观测了四-4-(2,4-二特戊基苯氧基)酞菁铜(CuPc(Dt-PP)_4)在银岛膜上的LB单分子层的表面增强共振拉曼散射(SERRS)光谱。比较其固体粉末的共振拉曼散射(RRS)光谱,讨论了酞菁铜分子大环在载片表面的取向及其可能的原因。1 实验CuPc(Dt-PP)_4样品由陈文启等合成,经元素分析、IR、NMR、色谱等研究确认其结构如图1所示.银岛膜用真空蒸镀法制备在玻璃载片上。用同时蒸镀在铜网上的银膜的透射电 相似文献
14.
The high-pressure behaviors of SmFeO3 are investigated by angle-dispersive synchrotron X-ray powder diffraction under a pressure of up to 40.3 GPa at room temperature. The crystal structure of SmFeO3 remains stable at up to the highest pressure. The different pressure coefficients of the normalized axial compressibility are obtained to be βa = 0.60 × 10-3 GPa-1,βb = 0.79 × 10-3 GPa-1, βc = 1.28 × 10-3 GPa- 1, and the bulk modulus (B0) is determined to be 293(3) GPa by fitting the pressure-volume data using the Birch-Murnaghan equation of state. Furthermore, the larger compressibility of the FeO6 octahedra suggests the evolution of the orthorhombic structure towards higher symmetry configuration at high pressures. 相似文献
15.
利用金刚石对顶砧(DAC)技术和显微 Ramana 光谱原位测量技术,在0~33.1 GPa 压力范围对 AIN 纳米线进行了高压相变研究.在24.4 GPa 附近,A1(LO)振动模式呈现出较大的非对称性宽化的特征,表明发生了六角纤锌矿到立方岩盐矿的结构转变.岩盐矿结构 AIN 纳米线的无序声子散射导致了高压相的Raman 散射信号.卸压后,高压相的 Raman 光谱特征被保留下来.根据纤锌矿结构 AIN 纳米线的振动模式频率随压力的变化关系,讨论了 AIN 纳米线和体材料在转变路径上的区别,并计算了纤锌矿结构中对应不同声子模式的格林爱森常数. 相似文献
16.
研究水的热力学状态方程,对于理解地球及行星科学等起着重要作用,但由于高温高压区域的实验数据较少,该区域的状态方程主要依赖于由低压部分外延或分子动力学模拟计算得到。采用布里渊散射技术测量熔解曲线附近液态水的声速,低温区采用电加热系统,高温区采用激光加热布里渊散射系统,分析比较了由实验测量得到的声速值与用经验状态方程计算的结果之间的差别。结果表明,在温度不超过673 K、压力不超过6.0 GPa的范围内,Abramson方程的计算结果与实验测量结果在误差范围内一致,而Saul 和IAPWS-95的预言值比实验测量值偏高,并且温度越高偏差越大。在压力为21 GPa、温度为890~1 100 K时,实验测量出的水的声速比状态方程预言的结果偏高。 相似文献
17.
18.
Structural and spectroscopic properties of Sr 2 ZnTeO 6 (SZTO) were investigated by angle-dispersive synchrotron X-ray powder diffraction and Raman spectroscopy in a diamond anvil cell up to 31 GPa at room temperature. Although SZTO remained stable up to the highest pressure, the different pressure coefficients of the normalized axial compressibility were obtained as βab =8.16×10-3 GPa-1 and βc =7.61×10-3 GPa-1 . The bulk modulus B0 was determined to be 190(1) GPa by fitting the pressure-volume data using the Birch-Murnaghan equation of state. All the observed Raman modes exhibited a broadening effect under high pressure. The vibrational band υ1 around 765 cm-1 , which is associated with the Te-O stretching mode in the basal plane of the TeO6 octahedron had the largest pressure coefficient, and the Grüneisen parameters for all the observed phonon modes were also calculated and presented. These parameters could be used to measure the amount of uniaxial or biaxial strain, providing a fundamental tool for monitoring the magnitude of the shift of phonon frequencies with strains. 相似文献
19.
20.