Isotope effect on radiative thermal transport

Isotope effects on heat conduction and convection have been known for decades. However, whether thermal radiation can be isotopically engineered remains an open question. Here, we predict over 3-orders-of-magnitude variation of radiative flow with varying isotopic compositions polar dielectrics at room temperature. We reveal this as isotope mass effect which induce phonon line shift broadening that in turn affect phonon-mediated resonant absorption both the near far field. In contrast, is negligible metals doped semiconductors largely depend free carriers. also discuss role temperature regard to surface mode excitation.