Depth-dependent phase change in Gd2O3 epitaxial layers under ion irradiation

Abstract

Epitaxial Gd2O3 thin layers with the cubic structure were irradiated with 4-MeV Au 2+ ions in the 10 13-10 15 cm-2 fluence range. X-ray diffraction indicates that ion irradiation induces a cubic to monoclinic phase change. Strikingly, although the energy-deposition profile of the Au 2+ ions is constant over the layer thickness, this phase transformation is depth-dependent, as revealed by a combined X-ray diffraction and ion channeling analysis. In fact, the transition initiates very close to the surface and propagates inwards, which can be explained by an assisted migration process of irradiation-induced defects. This result is promising for developing a method to control the thickness of the rare-earth oxide crystalline phases.

Engineering strain and conductivity of MoO3 by ion implantation

“…Regarding our results, these suboxide phases are first observed in the fluence range corresponding to the first strain relaxation and probably contribute to this strain saturation. In fact, phase changes upon ion implantation have been observed in other oxides such as Gd2O3 and Ga2O3 [64,65]. When region I and II become saturated with extended defects including suboxide phases, defects start to migrate towards deeper regions.…”

Effects of Kr and Xe ion irradiation on the structure of Y2O3 nanoprecipitates in YBCO thin film conductors

“…Several experimental techniques can be used to gather information on the electronic stopping power threshold or the size of the region damaged by irradiation like Rutherford backscattering spectrometry in channeling geometry [27,28], atomic force microscopy [29,30], profilometry [31], X-ray diffraction [32], Mössbauer spectroscopy [33], transmission electron microscopy [34,35]. Their results are most often partial and require indirect interpretation based on models with exception of transmission electron microscopy (TEM) that provides a direct access to morphological and structural information to the micro-to atom scale.…”

Improving crystal quality of Er-doped Gd2O3 grown on a Si(111) substrate by inserting a bifunctional GdOx layer

“…3(a) compares the (444) peaks of samples A and B prepared with t Gd = 7.5 Å. Laue fringes are clearly observed for sample B, whereas they are barely discernible for sample A, consistent with previous reports. [34][35][36] The thickness of the Er:Gd 2 O 3 layer in sample B is estimated to be 428 Å from the intervals of the fringes. Assuming that the initial 15 Å-thick layer is less homogeneous than the remaining layer in sample Ba reasonable assumption considering that the RHEED images with superstructure diffraction appeared only after 1 minthe coherent Er:Gd 2 O 3 thickness estimated above (428 Å) is in excellent agreement with that from the growth rate (435 Å = 450-15 Å).…”