Analysis of nanostructure and nanochemistry by ASAXS: Accessing phase composition of oxyfluoride glass ceramics doped withEr3+/Yb3+

Abstract

Here, we describe the analysis of the nanostructure and average chemical compositions of each phase present in an oxyfluoride glass ceramic, which is composed of fluoride nanocrystals and an oxide glass matrix. The overall composition of the oxyfluoride glass ceramic as prepared is 21.1%SiO 2 6.5%B 2 O 3 7.0%Al 2 O 3 21.0%PbF 2 14.3%CdF 2 11.0%YbF 3 0.5%ErF 3 11.0%PbO 7.6%CdO ͑mole %͒. Nanocrystals begin to grow at temperatures above the glass transformation temperature at 678 K as observed by x-ray diffraction. We report results from anomalous small-angle x-ray scattering taken at energies of x-ray absorption edges of Er, Yb, Pb, and Cd. By nonlinear regression of the scattering curves obtained from different edges simultaneously, the nanocrystals were found to be describable as polydisperse spheroids. The length of the smaller axis was found to be 6.4Ϯ 1.4 nm while the larger axis was found to be 17.7Ϯ 3.9 nm. By analyzing the scattering contrast as a function of the x-ray energy we found cadmium only in the glass matrix.

Transparent oxyfluoride glass ceramics

“…-infrared (IR) and Raman spectroscopy; -nuclear magnetic resonance spectroscopy (NMR); -anomalous small-angle X-ray scaterring (ASAXS) [208].…”

Structural analysis of Fe–Mn–O nanoparticles in glass ceramics by small angle scattering

“…The size distributions of particles evaluated by fitting of the nuclear and magnetic scattering are shown in Figure 5. Quantitative information about the composition and structure can be estimated by using the ASAXS technique [21]. The quantitative information is obtained by fitting the ASAXS curves and the experimental relative contrasts by two separate fitting routines as described in the theory section.…”

“…In ASAXS, the variation of the scattering power of specific element helps in determining the quantitative information on the distribution of that specific element in the nanoparticles and the respective phase compositions as well as the volume fractions [12,21,22]. In ASAXS measurements, the energy dependent atomic scattering amplitudes play an important role.…”

Investigation of Energy‐Relevant Materials with Synchrotron X‐Rays and Neutrons

“…[126] ASAXS has recently been demonstrated to provide useful information about chemical compositions on the nanometer scale. [127,128] As heterogeneous precious metal catalysts mostly consist of the nm-sized metal particles supported on chemically inert carriers, [129,130] ASAXS is an ideal tool for their characterization. To deduce an applicable structural model of the nanoparticles in the aforementioned system, a RuSe x catalyst with 40 wt% Ru and 14 wt% Se reduction-annealed at 800 8C was characterized in detail by ASAXS.…”