Contributions of electron and phonon transport to the thermal conductivity of GdFeCo and TbFeCo amorphous rare-earth transition-metal alloys

Abstract

We experimentally investigate the electron and phonon contributions to the thermal conductivity of amorphous GdFeCo and TbFeCo thin films. These amorphous rare-earth transition-metal (RE-TM) alloys exhibit thermal conductivities that increase nearly linearly with temperature from 90 to 375 K. Electrical resistivity measurements show that this trend is due to an increase in the electron thermal conductivity over this temperature range and a relatively constant phonon contribution to thermal conductivity. We find that at low temperatures ($90 K), the phonon systems in these amorphous RE-TM alloys contribute $70% to thermal conduction with a decreasing contribution as temperature is increased. V

Temperature-dependent nanoindentation response of materials

“…As shown in Fig. 1, an increase in temperature leads to increased activities of phonons (in crystalline insulators and some semi-conductors), electrons (in metal and some semi-conductors), propagons, diffusons, and locons (in amorphous non-metallic materials), [11,12] which in turn contribute to additional atomic displacements, an increase in the average interatomic distance, and a decrease in the restoring forces due to thermal expansion. [13][14][15][16] While increasing the dislocation mobility, a higher temperature lowers the minimum stresses required for homogeneous dislocation nucleation, dislocation gliding in a lattice, and breaking dislocation locks.…”

Phonon transport in aluminum and silicon film pair: laser short-pulse irradiation at aluminum film surface

“…They showed that that phonons contribute less than 1.0% to the bulk thermal conductivity at room temperature and their relative contribution to the conductivity and its variation with film thickness had a significant effect on the overall film resistance of metallic films. Contributions of electron and phonon transport to the thermal conductivity of amorphous rare earth transition metal alloys were studied by Hopkins et al [11]. They showed that alloys exhibited thermal conductivities that increased nearly linearly with temperature from 90 to 375 K, which was associated with the increase in the electron thermal conductivity over this temperature range.…”

Functional Property Evaluation of Crystalline Materials using Density Functional Theory: A Review

“…While focusing on electronic and thermal property prediction of metals, the main contribution for both aspects result from electronic contributions, where, for non-crystalline insulator materials, thermal properties arise mainly due to phononic contributions. Therefore, understanding electronic behavior in a crystalline material with free electron dominance is an inherent interest [4] along with phononic dominance in low free electron material. Study of electronic behavior of any material starts from the band structure predictions [5].…”