Correlation between the local stress and the grain misorientation in the polycrystalline Al₂O₃ measured by near-field luminescence spectroscopy

Abstract

Owing to its high spatial resolution, near-field spectroscopy is a useful method for sensing the stress in a narrow region of submicron order. Here, on the basis of the highly resolved images obtained by near-field luminescence spectroscopy, we propose a statistical method of analyzing grain anisotropy-induced stress in polycrystalline Al 2 O 3 . We focus on two characteristics of a spectra: the intensity ratio and peak shift of luminescence of two lines (R 1 and R 2 ) from Al 2 O 3 to discuss crystal orientation and stress, respectively. By incorporating the concept of the crystal misorientation parameter using intensity ratio, an apparent correlation between the magnitude of stress and the misorientation is found. This correlation analysis provides an important insight for the investigation of local thermal stress in Al 2 O 3 .

Scanning Tunneling Measurements in Membrane-Based Nanostructures: Spatially-Resolved Quantum State Analysis in Postprocessed Epitaxial Systems for Optoelectronic Applications

“…A STM/STS built-in combination of spatial high-resolution scanning capability and electronic response is strongly desirable as complementary to other scanning techniques such as scanning near-field optical microscopy (SNOM). This energy-resolved technique strongly depends on the quantum efficiency of the studied material (for direct gap optical emissions) and/or on the cross section of active Raman states (for inelastic scattering studies) . Other scanning probe techniques that use probes in direct contact with the sample (or in periodic contact) such as conductive atomic force microscopy (C-AFM) suffer, among other ambient operational limitations, from the setback of introducing additional Schottky barriers on the spectroscopic signal, avoided in the tunneling regime.…”

“…Suitable techniques to compare single nanostructure responses to that of an ensemble of nano-objects are then required to operate under real conditions. In this sense, the use of radiation such as visible and infrared light, providing measurements of optical response or vibrational properties were successfully employed in a broad class of materials, making Raman, infrared, and visible spectroscopies the common background tools for the exploration of materials. These radiation-based techniques have been driven to the nanoscale throughout the use of near-field microscopes, − where a metallic tip serves as the antenna to capture the response of the material under illumination.…”

Asymmetric Line Shape of Near-field Luminescence Spectrum Induced by Stress in Al2O3

“…Incorporating the near-field system, which enables optical sensing beyond the diffraction limit, in luminescence spectroscopy has also paved the way to further improvement of spatial resolution up to 30-500 nm. (4)(5)(6) This provides us a method to explore the important correlations between nano/micro-structures and stresses. (6) The accuracy of stress sensing is influenced not only by measurement conditions, but also by spectral analysis.…”

“…(4)(5)(6) This provides us a method to explore the important correlations between nano/micro-structures and stresses. (6) The accuracy of stress sensing is influenced not only by measurement conditions, but also by spectral analysis. Thus, to develop the stress analysis methodology, a large amount of time for investigation is necessary.…”