Atomistic Origin of Lattice Softness and Its Impact on Structural and Carrier Dynamics in Three Dimensional Perovskites

The soft lattices of lead-halide perovskites (LHPs) are responsible for their unique material properties, including polaron formation, defect tolerance, anharmonic vibration, and large electrostrictive response, which result in exotic carrier...

Estimation of Van der Waals Interaction Using FTIR Spectroscopy

Van der Waals (vdW) interaction is one of the important properties in the composite. The usual measurement used to investigate the vdW interaction between filler and polymeric binder is FTIR spectroscopy where the result obtained is the band shift appearance, however, it has not been used yet to estimate the vdW magnitude. Using the Lennard-Jones potential, we developed a new analysis method to obtain approximately its magnitude and further the distance between filler atoms and polymeric group. We used our model proposed to several data reported by some authors, and interestingly we also found an appearance of anharmonic vibration of the atoms.

Study of lattice vibration and thermal conductivity of BiCuSeO from first-principles calculations

ABSTRACTThe BiCuSeO has been proved to be one of the best oxide-based thermoelectric materials in recent years. Its electric properties have been widely studied, yet the lattice thermal conductivity was only discussed roughly. Our investigation suggests that the anharmonic vibration and the interlayer-interaction plays the crucial role in reducing the intrinsic lattice thermal conductivity. The thermal conductivity has been calculated based on quasi-harmonic approximation and detailed contribution have been discussed. The calculated data have good agreement with the experimental data.