Project Title

Mechanical behavior in ceramics with unusual thermo- mechanical properties

PI

Cristian V. Ciobanu

Email

cciobanu@mines.edu

Department

Mechanical Engineering

Project summary

The study of materials with unusual properties offers to provide new insights into structure-property relationships and promise in the design of novel composites with tailored properties. In this spirit, we have chosen to study beta-eucryptite, a technologically relevant lithium aluminum silicate (LAS) that exhibits negative thermal expansion, radiation tolerance, one-dimensional lithium ion conduction, and pressure-induced amorphization under moderate applied pressures. These exotic physical properties make beta-eucryptite suitable for various specific applications like heat exchangers, ring laser gyroscopes, and precision optical devices. Apart from these commercial uses, recently I2-eucryptite based solid solutions have been identified to be good candidates for application in (a) fuel coatings and reactor blankets in nuclear reactors, and (b) solid-state electrolyte in lithium ion batteries. Furthermore, it is also reported to undergo a reversible pressure-induced transformation (beta-to-epsilon) at moderate pressures ~0.8 GPa with possible applications in designing transformation-toughened ceramics. Although a number of spectroscopic studies have been employed to observe these intriguing phenomena, the atomic-scale mechanisms governing the anomalous response of beta-eucryptite to changes in environment like temperature, pressure and exposure to radiation are still unclear. The goal of this project is to unravel these mechanisms via a combination of density functional calculations and atomistic simulations that would contribute to a long-term ambition of designing novel LAS composites with desired physical properties

Commercial software

VASP

Open Source software

LAMMPS