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# Module Code - Title:

PH4042 - THERMAL PHYSICS

2022/3

3

2

1

0

4

6

N

PH4131

# Rationale and Purpose of the Module:

The purpose of this module is to enhance students' understanding of key concepts and models associated with thermal physics. The objectives are to first present a general thermodynamics framework, then to introduce statistical concepts followed by analysis of specific physical models.

# Syllabus:

Temperature: thermal equilibrium; the zeroth law; equations of state; temperature scales. [First law of thermodynamics]: internal energy; heat and heat capacity; reversible processes and work; free expansion and Joule's law. [Second law of thermodynamics]: Carnot cycles, efficiency; thermodynamic temperature scale. [Entropy]: Clausius inequality and entropy; principle of increasing entropy; central equation of thermodynamics; entropy of an ideal gas. [Thermodynamic potentials and Maxwell relations]: internal energy U; enthalpy H; Helmholtz free energy F; Gibbs free energy G; energy equations; availability A and useful work; mechanical, magnetic & electrolytic systems. [Change of phase]: chemical potential; Clausius-Clapeyron equation; nucleation; Gibbs phase rule. [Microstates and macrostates]: statistical weight of a macrostate; Boltzmann definition of entropy; entropy and disorder. [Equilibrium of an isolated system]: magnetic dipole lattice; Schottky defects. [Equilibrium of a system in a heat bath]: the partition function and the Boltzmann distribution; equivalence of thermodynamic and statistical quantities; the classical gas; heat capacities of solids; perfect quantal gas; Planck's law; thermodynamics of black body radiation. [Equilibrium of a system with variable particle number]: Gibbs distribution; Fermi-Dirac and Bose-Einstein distributions; Bose-Einstein condensation; Fermi energy; density of states; electrons in metals.

# Learning Outcomes:

## Cognitive (Knowledge, Understanding, Application, Analysis, Evaluation, Synthesis)

On successful completion of this module, students should be able to: - Define key concepts including temperature, entropy, state function, partition function. - State and apply the laws of thermodynamics. - Calculate entropy in simple cases which include the ideal gas and a defect containing crystal. - Solve problems from information given involving the use of the central equation of thermodynamics, thermodynamic potentials and Maxwell's relations. - Derive from first principles, and apply the Boltzmann and the Gibbs distributions for systems in equilibrium in a heat bath. - Define and apply the Fermi-Dirac and Bose-Einstein distributions.

## Affective (Attitudes and Values)

- Integrate the concepts of entropy and energy to the analysis and properties of real physical systems.

## Psychomotor (Physical Skills)

- Skillfully perform experiments and record and present data.

# How the Module will be Taught and what will be the Learning Experiences of the Students:

Students will learn via interactive lecture, laboratory, experiential tutorial and problem based private study.

# Prime Texts:

Finn, C.B.P. (1993) Thermal Physics , Chapman and Hall
Mandl, F. (1988) Statistical Physics , Wiley

# Other Relevant Texts:

M T Laugier (2008) Thermal Physics , unpublished notes
Schroeder, D. V. (2004) An Introduction to Thermal Physics , Pearson Education

Spring - 09/10