Specific heat study of R2RhIn8 (R=Y, La, Lu) compounds

•Single crystals of R2RhIn8 (R = Y, La, Lu) were grown from an indium flux.•All compounds reveal presence of the low energy phonons.•We report Debye and Einstein temperatures describing phonon specific heat.•The electronic structure calculations were performed based on DFT.•Performance of GGA and LSDA methods was compared with respect to experimental data.

We present a detailed specific heat analysis of the non-magnetic R2RhIn8 (R=Y, La, Lu) compounds, crystallizing in the tetragonal Ho2CoGa8-type structure. We focus on the lattice contribution and analyze the characteristic parameters in the Debye and Einstein models. The most prominent feature is the presence of low energy phonons in these compounds. We also give details about the single crystal preparation and structural parameters. First-principles electronic-structure calculations based on density-functional theory have been performed and compared with available experimental structural and electronic data.