# Material properties (thermodynamics)

The thermodynamic **properties of materials** are intensive thermodynamic parameters which are specific to a given material. Each is directly related to a second order differential of a thermodynamic potential. Examples for a simple 1-component system are:

**Compressibility**(or its inverse, the**bulk modulus**)

- Isothermal compressibility

- Adiabatic compressibility

**Specific heat**(Note - the extensive analog is the**heat capacity**)

- Specific heat at constant pressure

- Specific heat at constant volume

**Coefficient of thermal expansion**

where *P* is pressure, *V* is volume, *T* is temperature, *S* is entropy, and *N* is the number of particles.

For a single component system, only three second derivatives are needed in order to derive all others, and so only three material properties are needed to derive all others. For a single component system, the "standard" three parameters are the isothermal compressibility , the specific heat at constant pressure , and the coefficient of thermal expansion .

For example, the following equations are true:

The three "standard" properties are in fact the three possible second derivatives of the Gibbs free energy with respect to temperature and pressure.

## References

Callen, Herbert B. (1985). *Thermodynamics and an Introduction to Thermostatistics* (2nd Ed. ed.). New York: John Wiley & Sons. ISBN 0-471-86256-8.