Elective course: Physical properties of crystals

First semester, 2019 – 2020

Lecturer:  

Dr Semën Gorfman

(129, Wolfson Building for Mechanical Engineering, gorfman@tauex.tau.ac.il)

Language:

English

The goal of this course:

To become familiar with the physical properties of crystalline materials, their description and applications.

Prerequisites:

All the basic courses in mathematics and physics.

Introduction to crystallography and structure analysis.   

Format of the course:

3 hours per week of lecture (including some examples exercises, solved in the classroom). You will get homework assignments to be submitted individually.   

Grading and exam:

The final grade will be calculated from the exam (80 %) and the solved homework (20%). However, many additional extra-tasks will be available throughout the course and there will be opportunity to collect sufficient number of points during the semester.

Tentative topics:

Part I. Mathematical Introduction

Introduction: Definition of materials properties. Physical properties of crystals. 

Operations with tensors: The use of tensors for the description of materials properties. Transformation of coordinate systems and tensor components.

Symmetry: Definition of symmetry, symmetry operations, mathematical representation of symmetry operations. The role of symmetry of the structures for materials properties. Neumann principle.

Symmetry and physical properties of crystals: Symmetry of crystals. Bravais types of lattices, crystal systems and point symmetry groups.

Part II. Physical properties of materials

Electrocaloric and dielectric properties of crystals:  Heat capacity, pyroelectric effect, electrocaloric effect and dielectric susceptibility.  Polar and non-polar crystals. Applications.

Strain and stress tensors: Description of materials deformation and external forces by second rank tensors. Tensile and shear strains / stresses.

Elastocaloric properties of crystals: Thermal expansion and piezocaloric effect. Thermodynamics of elastocaloric properties and their relation to crystal symmetry. Negative thermal expansion coefficients. Preparation of cuts for zero thermal expansion.     

Piezoelectric properties crystals: Direct and converse piezoelectric effects. Voigt notations. Crystal symmetry and piezoelectric effect. Representation surfaces.

Piezoelectric ceramics and applications of piezoelectric effect: Preparation, symmetry and properties of piezoelectric ceramics. Applications of piezoelectric materials.

Elastic properties of crystals: elastic stiffness and elastic compliance. Voigt notations for elastic coefficients. Bulk compressibility, Young modulus and Poisson ratio.

Propagation of elastic waves through crystalline materials:  Mathematical description of elastic waves. Calculation of sound velocities and measurement of elastic coefficients.   

Part III (Optional). Advanced physical properties of materials

Optical properties of crystals:  Propagation of light through crystalline solids. Optical birefringence. Optical indicatrix. Optical birefringence and crystal symmetry. Applications.

Second Harmonic Generation (SHG): Definition of the property and SHG-tensors. Voigt notations. Crystal symmetry and SHG. Applications

Exotic physical properties of crystalline materials:  Quadratic electrostriction, flexoelectric effect.

Recommended literature:

[1]. J.F. Nye. Physical properties of crystals and their representations by tensors and matrices. Oxford University Press.  1985.

[2]. Robert E Newnham. Properties of Materials : Anisotropy, Symmetry, Structure. Oxford University Press. 2005.

[2]. International Tables for Crystallography, Volume D. International Union of Crystallography, 2016.