In-Depth Thermal Conductivity Profile of Ion-Irradiated Zirconium Carbide using Scanning Thermal Microscopy

The in-depth thermal conductivity (k) profile in a proton-irradiated zirconium carbide (ZrC) sample has been directly measured for the first time using scanning thermal microscopy. The measured k profile is shown to be independent of imperfect sample topography and constructed by overlaying several thermal line profiles. The shape of the numerically calculated, irradiation damage profile compares well with the resulting profile of k degradation. A relatively thick and constant diminished k value is revealed through the majority of the damaged zone, consistent with characteristics of proton irradiation. A sharp transition of the thermal signal to the non-irradiated material was found at the rear of the profile, with no indication of the very thinly peaked damage seen in the numerically calculated damage profile. A rudimentary calibration of the measured thermal signal on the sample indicates ≈ 66 % degradation of k in the proton-irradiated zone of the ZrC sample