# NERSC Initiative for Scientific Exploration (NISE) 2011 Awards

## Development of CALPHAD type approach to thermal conductivity aided by first-principles phonon approach

### Huazhi Fang, Pennsylvania State University

**Associated NERSC Project: Investigations of phase stability and thickness issues in interconnects for solid oxide fuel cells through first principles calculations and computational thermodynamic modeling (m1215)**

NISE Award: | 500,000 Hours |

Award Date: | June 2011 |

The proposal aims to develop a fundamental database of thermal conductivity, which is essential to the design of materials involved in the process of heat transfer. High thermal conductivity materilas are highly demanded in many fields, such as to facilitate cooling in microelectronics. Whereas low thermal conductivity materials are also required in heat preservation applications.

Thermal conductivity is of a fundamental physical property of materials. Materials with high thermal conductivity are being pursued in various fields, such as mircoelectronics, thermoelectrics and turbine engine. Whereas, low thermal conductivity is required for materials with the fucntion of heat preservation. The purpose of current proposal is to develop a database of thermal conductivity with the Calphad approach aided by first-principles phonon approcah. The Calphad type approach is a valuable methodology for prediction of phases and thermodynamic type properties related to the phases present in complex multi component alloys. The first-principles approach is used to calculate the input data for the Calphad approach. The quantities to be modelled by the first principle calculation include the group velocity, the phonon lifetime, the phonon Grüneisen parameter, and the Debye frequency.

For simple systems, the phonon properties will be calculated using first-principles phonon approach for both polar materials and metals. For more complicated system, the CALPHAD type approach will be employed to model the transferable force constants in calculating phonon properties. The systems we will firstly focus on are the Al-based, Mg-based, Ni-based and Ti-based alloys.