**5. Conclusions**

We have measured the lattice disordering of polycrystalline SiO2, ZnO, Fe2O<sup>3</sup> and TiN films, as well as the sputtering yield of TiN, by high-energy ion impact. It is found that lattice disordering is caused by electronic excitation and the degradation of the XRD intensity fits to the power-law on the electronic stopping power. The exponent in the fit of the XRD degradation is comparable with that of the electronic sputtering yield for these films, as well as the published results of WO3, KBr and SiC, implying that both lattice disordering and sputtering originate from similar mechanisms. In the case of Fe2O3, on the other hand, the exponent of the lattice disordering is larger by twice than that of the sputtering (the exponent for the sputtering is close to unity). The exciton mechanism seems to work for Eg > 3 eV, with some exceptions, and the elastic constant is examined as another scaling parameter for the electronic sputtering yields. A possibility of electron– lattice coupling is discussed based on a crude estimation that an atomic displacement comparable with the vibration amplitude due to Coulomb repulsion during the short neutralization time in the ionized region along the ion path can be attainable and, thus, the generation of a highly excited state coupled with the lattice is highly achievable, resulting in atomic displacement.

**Author Contributions:** Conceptualization and writing, N.M.; investigation, M.S., S.O. and B.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** One of the authors (N.M.) thanks for utilization of XRD equipments of RIGAKU ULTIMA IV and RAD IIc at Radioisotope Research Center, Nagoya University and of AN Van de Graaff accelerator, Nagoya University for Rutherford backscattering spectroscopy (RBS) measurement. High-energy ion irradiation has been performed using a TANDEM accelerator at Tokai Research Center, JAEA.

**Conflicts of Interest:** The authors declare no conflict of interest.
