A Possible Origin of Glasslike Thermal Conductivity in Phase‐Change Memory Crystals.

Thermal processes play a crucial role in a variety of applications ranging from thermoelectrics, to thermal barrier coatings for turbines to memory devices, where materials with low thermal conductivity κ are essential for energy savings. By comparing two phase‐change materials, Ge2Sb2Te5$\left(\text{Ge}\right)_{2} \left(\text{Sb}\right)_{2} \left(\text{Te}\right)_{5}$ and Ga2Te3$\left(\text{Ga}\right)_{2} \left(\text{Te}\right)_{3}$, that have very similar thermal conductivities despite very different structures and bond strengths, it is argued that their phonon‐glass electron‐crystal properties stem from randomly oriented nonbonding lone–pair orbitals subtended at chalcogen atoms surrounding intrinsic vacancies. [ABSTRACT FROM AUTHOR]