Three-Dimensional In-Situ Imaging of Single-Grain Growth in Polycrystalline Films

Abstract

Strain and interactions at grain boundaries during solid-phase crystallization are known to play a significant role in the functional properties of polycrystalline materials. However, elucidating three-dimensional nanoscale grain morphology, kinetics, and strain under realistic conditions is challenging. Here, we image a single-grain growth during the amorphous-to-polycrystalline transition in technologically relevant transparent conductive oxide (TCO) film of In2O3:Zr with in-situ Bragg coherent X-ray diffraction imaging and transmission electron microscopy. We find that the Johnson-Mehl-Avrami-Kolmogorov theory, which describes the average kinetics of polycrystalline films growth, can be applied to the single grains as well. The quantitative analysis stems directly from imaging results. We elucidate the interface-controlled nature of the single-grain growth in thin films and reveal the surface strains which may be a driving force for anisotropic crystallization rates. Our results bring in-situ imaging with coherent X-rays towards understanding and controlling the crystallization processes of TCOs and other polycrystalline materials at the nanoscale.

Broadband Nonlinear Optical Response of Indium–Zirconium Oxide in the Epsilon‐Near‐Zero Region

“…Based on previous work on IZrO and further characterization of the films, the possible causes of the gradient can be linked to: i) a larger density of defects at the substrate/IZrO film interface, as suggested by the lower mobility in Table 1; ii) a strain gradient as reported recently in Ref. [39]; or iii) a nonuniform composition or dopant distribution, as suggested by Rutherford Backscattering Spectrometry (RBS) measurements. The RBS results show that In/Zr ratios measured at 2 and 5 MeV are not in agreement within the measurement accuracy (see Section , Supporting Information).…”