Difference between revisions of "Topics:PCG Portfolio"

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(New page: ==PCG – Educational portfolio== Crystal structures and their transformations • Space Group Symmetry • Symmetry lowering • Structural phase transitions – Landau theory • Rep...)
 
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Crystal structures and their transformations
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Revision as of 09:50, 2 March 2007

PCG – Educational portfolio

Crystal structures and their transformations

• Space Group Symmetry • Symmetry lowering • Structural phase transitions – Landau theory • Representation analysis • Tensors in crystallography • Charge density • Modulated crystal structures – Superspace group approach

Elastic properties

• Strain-stress relations • Pressure effects

Bulk properties

• Thermal expansion in crystals • Atomic displacement parameters: relationship with phonons and specific heat.

Magnetic structures

• Description of magnetic structures – propagation vectors • Magnetic symmetry analysis – irreps and coreps • Spin density determination with polarised neutrons. • XYZ and spherical polarimetry applied to crystalline materials

Microstructure analysis

• Strain effects • Particle size and distribution • Stacking faults • Texture

Diffraction methods

• CW neutron and x-rays • TOF neutrons • Energy dispersive x-rays • Diffraction imaging – TEDDI etc. • Time-resolved crystallography • Crystallography under high pressure • High-magnetic-field crystallography • SX techniques: Laue, time-sorted Laue…

Data analysis

• Refinement of structural parameters –least square – Rietveld • Direct-space methods – simulated annealing • Single-crystal techniques – twinning

Instrumentation

• Diffraction geometries • Principles of TOF/CW instrument design • Detector technologies of X-rays and neutrons