ANGLE-DEPENDENT MEASUREMENTS OF ELONGATED PLATINUM NANOCRYSTALS USING SMALL ANGLE X-RAY SCATTERING

Abstract

Elongated Pt nanocrystals (NCs) formed in SiO2 by ion implantation, thermal annealing and swift heavy ion irradiation (SHII) were analyzed by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) measurements. Transmission SAXS measurements were performed in samples aligned at different angles relative to the photon beam resulting in nonisotropic scattering and thus enabling the three-dimensional analysis of the NCs. Selected angular sectors of the detector were integrated and analyzed separately, leading to the individual evaluation of both the major and minor dimensions of the rod-shaped NCs. This method enables the use of well-established spherical models for the SAXS data analysis and yielded good agreement with TEM results. Corrections to the amplitude of the SAXS diameter distributions to overcome the disparities between the spherical models and the nonspherical particles are also presented.