Combined Analysis E-Book

Daniel Chateigner

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 631

Veröffentlichungsjahr: 2013

Beschreibung

This book introduces and details the key facets of Combined Analysis--an x-ray and/or neutron scattering methodology which combines structural, textural, stress, microstructural, phase, layer, or other relevant variable or property analyses in a single approach. The author starts with basic theories related to diffraction by polycrystals and some of the most common combined analysis instrumental set-ups are detailed. Powder diffraction data treatment is introduced and in particular, the Rietveld analysis is discussed. The book also addresses automatic phase indexing--a necessary step to solve a structure ab initio. Since its effect prevails on real samples where textures are often stabilized, quantitative texture analysis is also detailed. Also discussed are microstructures of powder diffraction profiles; quantitative phase analysis from the Rietveld analysis; residual stress analysis for isotropic and anisotropic materials; specular x-ray reflectivity, and the various associated models. Finally, the book introduces the combined analysis concept, showing how it is superior to the view presented when we look at only one part of the analyses. This book shows that the existence of texture in a specimen can be envisaged as a way to decouple ordinarily strongly correlated parameters, as measured for instance in powder diagrams, and to examine and detail deeper material characterizations in a single methodology.

Leseprobe

Table of Contents

Introduction

Acknowledgements

Chapter 1: Some Basic Notions About Powder Diffraction

1.1. Crystallite, grain, polycrystal and powder

1.2. Bragg’s law and harmonic reflections

1.3. Geometric conditions of diffraction, Ewald sphere

1.4. Imperfect powders

1.5. Main diffraction line profile components

1.6. Peak profile parameters

1.7. Modeling of the diffraction peaks

1.8. Experimental geometry

1.9. Intensity calibration (flat-field)

1.10. Standard samples

1.11. Probed thickness (penetration depth)

Chapter 2: Structure Refinement by Diffraction Profile Adjustment (Rietveld Method)

2.1. Principle of the Rietveld method

2.2. Rietveld-based codes

2.3. Parameter modeling

2.4. Crystal structure databases

2.5. Reliability factors in profile refinements

2.6. Parameter exactness

2.7. The Le Bail method

2.8. Refinement procedures

2.9. Refinement strategy

2.10. Structural determination by diffraction

Chapter 3: Automatic Indexing of Powder Diagrams

3.1. Principle

3.2. Dichotomy approach

3.3. Criterions for quality

Chapter 4: Quantitative Texture Analysis

4.1. Classic texture analysis

4.2. Orientation distribution (OD) or orientation distribution function (ODF)

4.3. Distribution density and normalization

4.4. Direct and normalized pole figures

4.5. Reduced pole figures

4.6. Fundamental equation of quantitative texture analysis

4.7. Resolution of the fundamental equation

4.8. OD refinement reliability estimators

4.9. Inverse pole figures

4.10. Texture strength factors

4.11. Texture programs

4.12. Limits of the classic texture analysis

4.13. Magnetic quantitative texture analysis (MQTA)

4.14. Reciprocal space mapping (RSM)

Chapter 5: Quantitative Microstructure Analysis

5.1. Introduction

5.2. Microstructure modeling (classic)

5.3. Bertaut-Warren-Averbach approach (Fourier analysis)

5.4. Anisotropic broadening: the Popa approach [POP 98]

5.5. Stacking and twin faults

5.6. Dislocations

5.7. Crystallite size distributions

5.8. Rietveld approach

Chapter 6: Quantitative Phase Analysis

6.1. Standardized experiments

6.2. Polycrystalline samples

6.3. Amorphous-crystalline aggregates

6.4. Detection Limit

Chapter 7: Residual Strain-Stress Analysis

7.1. Strain definitions

7.2. ε33 strain determination

7.3. Complete strain tensor determination

7.4. Textured samples

Chapter 8: X-Ray Reflectivity

8.1. Introduction

8.2. X-rays and neutrons refractive index

8.3. The critical angle of reflection

8.4. Fresnel formalism (specular reflectivity)

8.5. Surface roughness

8.6. Matrix formalism (specular reflectivity)

8.7. Born approximation

8.8. Electron density profile

8.9. Multilayer reflectivity curves

8.10. Instrumental corrections

Chapter 9: Combined Structure-Texture-Microstructure-Stress-Phase Reflectivity Analysis

9.1. Initial queries

9.2. Implementation

9.3. Experimental set-up

9.4. Instrument calibration

9.5. Refinement strategy

9.6. Examples

Chapter 10: Macroscopic Anisotropic Properties

10.1. Aniso- and isotropic samples and properties

10.2. Macroscopic/microscopic properties

Bibliography

Glossary

Abbreviations

Mathematical Operators

Index

First published 2010 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd27-37 St George’s RoadLondon SW19 4EUUKJohn Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USAwww.iste.co.ukwww.wiley.com

© ISTE Ltd 2010

The rights of Daniel Chateigner to be identified as the author of this work have been asserted by him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Chateigner, Daniel.

Combined analysis / Daniel Chateigner.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-84821-198-8

1. Chemistry, Analytic. 2. Solid state chemistry. 3. Crystals. I. Title.

QD75.3.C45 2010

548'.83--dc22

2010012973

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

ISBN 978-1-84821-198-8

Introduction

Recent developments in solid state chemistry and technology have made intensive structural analysis from single crystal diffraction a necessity. However, for many solids, single crystal growth is not easily undertaken and is sometimes impossible. When this is the case, or when structural defects cannot be overcome, the corresponding phases often have to be forsaken, due to the inherent difficulties of performing crystallographic characterization of polycrystals. Recently, powder diffraction techniques have progressed significantly, notably due to the Rietveld approach [RIE 69] and developments in computer science. Undoubtedly these developments are important in the study of solids that do not form large crystals, but also of all materials elaborated by classic solid state reactions, thin deposited structures, natural materials, such as clays, and more recently, nanomaterials in which the required properties are intimately linked to the stabilization of small crystals.

Since the publication of Rietveld’s method, several tens of thousands of structures have been refined and thousands have been resolved ab-initio from only the diffraction data of powder samples. The number of laboratories and industries using this technique, which is still fairly new when dealing with the incorporation of various formalisms as used in the combined approach, continually increases.

However, materials with specific properties are often elaborated from low symmetry phases, which are consequently anisotropic. The optimization of a property is then conditioned by the elaboration processes, in which the intrinsic microscopic anisotropy of the constituting crystals has to be maintained at the macroscopic level. These elaboration techniques are complex (alignment under uniaxial pressure, magnetic or electric fields, thermal gradients, flux or substrate growing, etc., and combinations of these) and sample preparation is frequently complicated and time-consuming. Obviously, it is preferable that the process of sample characterization should be non-destructive. Unfortunately, when samples are oriented, which was not often the case until recently, most of the characterization techniques (such as the Rietveld analysis of concerns here) require sample grinding. Very often this grinding is not acceptable, for the previously described reasons, but also in the case of rare samples (fossils, comets, etc.) or simply when grinding modifies the physical behavior of the samples themselves (thin films, residual stress materials, etc.). Sometimes grinding is simply not possible, imagine peeling off a 10 nm thick film from a substrate! In all these cases, combined analysis becomes essential.

The first chapter of this book is dedicated to some basic notions concerning diffraction by polycrystals. The various peak profiles used are described and for some of the most common combined analysis, the instrumental set-up is described in detail.

In the second chapter, powder diffraction data treatment is introduced. In particular, Rietveld analysis is detailed, including treatment of all the information provided by diffraction diagrams, in cases of samples not exhibiting texture, or with textures that are easy to treat.

The third chapter deals with automatic phase indexing, which is a necessary step that enables a structure to be elucidated ab-initio.

As its effect prevails on real samples where textures are often stabilized, quantitative texture analysis is detailed in the fourth chapter.

The fifth chapter is dedicated to microstructural aspects (isotropic and anisotropic crystal sizes and microdistortions) of the powder diffraction profiles.

In the sixth chapter, quantitative phase analysis from Rietveld analysis is introduced.

Chapter 7 describes residual stress analysis for isotropic and anisotropic materials.

Chapter 8 focuses on specular x-ray reflectivity and the various models associated with it.

Chapter 9 introduces the combined analysis concept, illustrating the difficulties encountered when we look at only one part of the analyses. Case examples are provided to illustrate the methodology.

Chapter 10 is dedicated to the anisotropic and tensorial macroscopic properties and their simulations to account for the distribution of crystallite orientations in samples.

This book does not intend to give the reader a complete description of the approaches provided, but is a basis for following the many concepts introduced over so many years, which are necessary to understand scattering patterns. Quantitative texture analysis is detailed in more depth than the other areas as texture appears to be the largest signal biaser.

Acknowledgements

I am indebted to Magali Morales (CIMAP-Caen) who constantly comes with new issues, criticisms, advice and proposals. She was the first to test the Combined Analysis using the CPS detector set-up when taking part in the ESQUI European project. This work should be understood within hers.

Luca Lutterotti (DIM-Trento) is entirely devoted to this thematic and programming, without him nothing could have been carried out.

Thanks to: Jesus Ricote (DMF-Madrid), Michele Zucali and Emmanuel Guilmeau (CRISMAT-Caen), who provided some of the worst samples to test; Salim Ouhenia (Physics Dept. Bejaia) for his work on CaCO3-PAA films and Charonia shell; Hans-Rudolf Wenk (DEPS-Berkeley) and Siegfried Matthies, who are pioneers in the field with the so-called “Rietveld-Texture Analysis”; Bachir Ouladdiaf, who was of so much constant help during the multiple stays at ILL needed to achieve these works. To all these people, please receive my warmest sympathy and friendship.

I wish to thank in particular M.L. Calzada (DMF-Madrid) for the preparation of PCT ferroelectric films; E. Derniaux and P. Kayser (ONERA-Paris) for the elaboration of AlN films; G. Leclerc, R. Bouregba and G. Poullain (CRISMAT-Caen) for the PZT film elaboration and hysteresis characterization; R. Whatmore (Cranfield University) for the elaboration of the spin coated PZT films; V. Bornand (Univ. Montpellier) for the elaboration of the LiNbO3 films; M. Bouguerra for the GaN-SiO2 composite elaboration and PL and PLE characterization; R. Kaptein and C. Krauss for the CaCO3 thin layer electrodeposition; C. Keller and E. Hug (CRISMAT-Caen) for the mechanical characterization of the polycrystalline Ni samples; S. Deniel and P. Blanchart (ENSCI-Limoges) for the elaboration of mullite composites and their mechanical characterization; F. Léon for his experimental help in MQTA; and O. Pérez (CRISMAT-Caen) for the fruitful discussions around superspaces.

This work was periodically ameliorated via remarks and notifications of mistakes. I would like to thank Piotr Ozga for this.

This work could not have been carried out without support (financial or contracts) from the following institutions and organizations:

– Ministère de l’Enseignement Supérieur et de la Recherche;

– Délégation Régionale à la Recherche et à la Technologie, Conseil Régional de Basse-Normandie;

– GdR Nomade: Groupement de Recherche “N’Ouveaux MAtériaux pour les DÉchets radioactifs”;

– CNRS-CSIC French-Spanish cooperation “Crystallographic texture influence on polycrystalline ferroelectric materials properties” (contract n° 16215, 2004-2005, 2004FR0030);

– the European Union project ESQUI “X-ray Expert System for microelectronic films Quality Improvements” within the GROWTH program (G6RD-CT99-00169);

– CNRS-CSIC French-Spanish cooperation “PTL, SBT and PTC ferroelectric film characterization” (contract n° 8540, 2000-2001, 2000FR0021);

– European Concerted Action “ELENA: ELEctroceramics from NAnopowders produced by innovative methods” (COST n° 539, 2005-2009);

– European Concerted Action “Application of ferroelectric thin-films for SAW devices” (COST n° 514, 1998);

– the Spanish advanced fellowship program “Ramón y Cajal” of the Spanish MCyT;

– the Spanish MCyT projects MAT2000-1925-CE and MAT2002-00463;

– the Spanish FINNOVA program (CAM);

– the MIND Network of Excellence “Multifunctional & Integrated Piezoelectric Devices” NoE 515757-2;

– the Mat 2005-01304 FEDER-MEC-Spain: “Materiales ceramicos ferroelectricos con alta deformacion bajo el campo electrico nuevas soluciones solidas con frontera de fases morfotropica y texturacion”.