High-resolution synchrotron X-ray diffraction

The present work summarizes opportunities of using high-resolution synchrotron and standard xrd techniques for structural characterization as well as for investigations of structure-property-relationships. xrd will be used to determine quantitatively the phase content of morphotropic pzt. Temperature dependent measurements provide information about the phase transformation of morphotropic donor doped pzt ceramics and high-resolution synchrotron X-ray diffraction gives information about the extrinsic and intrinsic contributions to the electric field induced strain, xrd results are finally compared with electrical measurements to analyze the interactions among microstructure, phase content and properties. 

A Quench D5niamics protocol (a combination of high temperature Molecular Dynamics and Energy Minimization techniques) is used for predicting the location of triethylmethylammonium (TEMA) cations in zeolite MFI. Rietveld refinement of the high-resolution synchrotron X-ray diffraction data confirms these predictions. The TEMA cations are located at the channels intersections in two different conformations with two ethyl groups located in the linear channel. 

Menou, N., Muller, Ch Baturin, I.S., Shur, V.Ya., and Hodeau, J.-L. (2005) Polarization fatigue in PbZro.45Tio.55Oj-based capacitors studied from high resolution synchrotron X-ray diffraction. J. Appl. Phys., 97, 064108. 

The five years since last considering specifically recent developments in X-ray and neutron diffraction methods for zeolites [1] have witnessed substantial progress. Some techniques, such as high resolution powder X-ray diffraction using synchrotron X-rays, have blossomed from earliest demonstrations of feasibility to widespread and productive application. Others, such as neutron powder diffraction, have shown steady progress. For still others, notably microcrystal diffraction, a variety of circumstances have contributed to extended gestation periods. Additionally, opportunities scarcely considered earlier (such as single crystal Laue diffraction, and certain developments in computer simulations that complement diffraction work) now command broad attention and warrant the commitment of substantial further investment. 

Two types of contributions to dielectric and piezoelectric properties of ferroelectric ceramics are usually distinguished [6], [9-12], One type is called an intrinsic contribution, and it is due to the distortion of the crystal lattice under an applied electric field or a mechanical stress. The second type is called an extrinsic contribution, and it results from the motion of domain walls or domain switching [8], To provide an understanding of material properties of pzt, several methods to separate the intrinsic and extrinsic contributions were proposed. These methods are indirect, and are based on measurements of the dielectric and piezoelectric properties of ferroelectric ceramics [8], [10-12], In the experiments reported in this paper a different approach is adopted, which is based on measurements of high-resolution synchrotron X-ray powder diffraction. The shift in the positions of the diffraction peaks under applied electric field gives the intrinsic lattice deformation, whereas the domain switching can be calculated from the change in peak intensities [13,14],... 

Eylem C, Hriljac JA, Ramamrrrthy V, Corbin DR, Parise JB (1996) Stmctirre of a zeolite ZSM-5-bithiophene complex as determined by high resolution synchrotron X-ray powder diffraction. Chem Mater 8 844-849... 

The main reason for the explosive development in in situ powder diffraction experiments is the development of high intensity synchrotron X-ray sources. The very high intensity allows good time resolution, which makes it possible to follow even very fast reactions. In addition, the accessibility of high energy X-ray radiation has enabled in situ studies in even thick walled steel eontainers, making it possible to study materials under operating conditions. 

Figure 1.11 High-angular-resolution synchrotron X-ray powder diffraction profiles of compositionally homogeneous Ce Zrj. Oj. Reprinted with permission from Yashima et al Copyright 1998 American Institute of Physics.

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