Advanced methods in diffraction
Advanced methods in diffraction
Academic year 2020/2021
- Course ID
- Linda Pastero (Lecturer)
- Degree course
- Scienza dei Materiali [LM-53]
- 2nd year
- Teaching period
- Second semester
- Course disciplinary sector (SSD)
- GEO/06 - mineralogy
- Type of examination
- Basics of crystallography and diffraction
Sommario del corso
After attending the course (theoretical lessons, practical activities and laboratory) the student will be able to:
(i) describe the main applications of X-ray diffraction.
(ii) describe the main instrumental configurations (laboratory instruments) with particular attention to the optics, related aberrations, and their effect on the experimental data.
(iii) apply the Rietveld technique through the use of different structural refinement programs illustrated in class (structural refinement, qualitative-quantitative analysis with the possible presence of the amorphous phase, analysis of mixtures of inorganic crystalline phases, textural analysis - stress, strain, orientation of the crystallites - on inorganic crystalline phases).
Results of learning outcomes
KNOWLEDGE AND UNDERSTANDING: The course aims to stimulate the student to understand the relationships between theoretical concepts of crystallography and diffraction and their experimental evidence.
APPLYING KNOWLEDGE AND UNDERSTANDING: A didactic path is proposed that goes from understanding to applying the concepts learned to:
(i) diffractometric analysis techniques from powders
(ii) Rietveld method for quantitative and quantitative phase analysis for industrial and environmental applications
(iii) Rietveld method for structural and textural analysis of inorganic materials.
Recap of crystallography: Crystalline systems and classes. Diffraction principles.
Diffraction from powders: Conventional sources, optics and detectors. Parafocusing and transmission geometries. Notes on non-conventional sources.
Qualitative analysis: Identification of crystalline phases in polycrystalline mixtures. Databases. Use of the free QUALX program for phase identification in crystalline mixtures.
The Rietveld method: Quantitative, structural, and textural analysis. Use of crystallographic databases. Use of structural refinement programs: an overview of the main structural refinement programs with particular reference to the free GSASII program. Notes on the indexing of crystalline phases with reference to the free programs EXPO and GSASII.
Laboratory: Acquisition of data on laboratory instruments for research and for routine analysis, with particular attention to the configurations of the optics and their effect on the experimental data. Notes on single-crystal diffraction.
Exercises: Identification of crystalline phases in polycrystalline mixtures. Exercises on structural and quantitative analysis: structural refinement of crystalline phases, multiphase mixtures, mixtures containing amorphous. Indexing of diffraction patterns. Pattern deconvolution and its crystallographic meaning
Lectures, Practice and Laboratory
Learning assessment methods
The oral exam consists of a discussion about the topics considered during the classes, starting from a practical case which can be an exercise about indexing, refinement, or qualitative-quantitative analysis.
If not in attendance, the exams will be performed orally on the Webex platform with active registration and screen sharing.
The teacher is available by appointment to discuss, repeat, and clarify the concepts explained in class.
The meetings will be scheduled in attendance or on the WebEx platform.
Suggested readings and bibliography
Hammond - The Basics of Crystallography and Diffraction. IUCr-Oxford Science Publications
R.A. Young – The Rietveld method. Oxford Science Publication
V.K. Pecharsky, P.Y. Zavalij - Fundamentals of powder diffraction and structural characterization of materials. Springer
Students are reminded of the prohibition of sharing and dissemination in any form of platform-loaded teaching materials and videoconferencing lessons: any action that violates this norm will be denounced by the teachers to the organs of the University and will be pursued according to the law.
In addition, the link to the videoconferencing lessons (webex and the like) must be exclusively through the institutional e-mail and using name and surname.
Please register for the course on the Moodle platform
The teaching material can be found on the Moodle platform. To find it please select "Vai a Moodle" at the end of this webpage.
LABORATORY PRACTICAL SESSIONS: PLEASE GO TO THE MOODLE PLATFORM, ENROLL AND CHECK THE FORM FOR THE LAB FREQUENCY AT THE BOTTOM OF THE WEBPAGE
The link to the streaming of the lessons is the following:
Lessons: from 01/03/2021 to 11/06/2021
- Enrollment opening date
- 11/02/2021 at 15:00
- Enrollment closing date
- 05/03/2021 at 15:00