Experimental TDPAC and Theoretical DFT Study of Structural, Electronic, and Hyperfine Properties in (¹¹¹In → )¹¹¹Cd-Doped SnO₂ Semiconductor: Ab Initio Modeling of the Electron-Capture-Decay After-Effects Phenomenon

Abstract

In this paper we investigate the effect of Cd doping at ultra-low concentrations in SnO 2 both experimentally, by measuring the temperature dependence of the electric quadrupole hyperfine interactions with time-differential perturbed angular correlation (TDPAC) spectroscopy using 111 Cd as probe nuclei, and theoretically, by performing first-principles calculations based on the density functional theory. TDPAC spectra were successfully analyzed with a time-dependent on-off model for the perturbation factor. These results show combined dynamic plus static interactions whose electricfield gradients were associated in this model to different stable electronic configurations close to the Cd atoms. The dynamic regime is then originated in fast fluctuations between these different electronic configurations. First-principles calculations results show that the Cd impurity introduces a double acceptor level in the top of the valence band of the doped semiconductor and produces isotropic outward relaxations of the nearest oxygen neighbors. The variation of the calculated electric-field gradient tensor as a function of the charge state of the Cd impurity level shows an interesting behavior that explains the experimental results, giving strong support from first-principles to the electron-capture after-effects proposed scenario. The electron-capture decay of the parent 111 In to 111 Cd as well as the double acceptor character of the 111 Cd impurity and the electric nature of the host are shown to contribute to the existence of these type of time-dependent hyperfine interactions.

Investigation of Ni/Ni3C Nanoparticle Synthesis for Application as a Catalyst in Carbon Nanostructure Growth

“…Additional information on PAC technique can be found elsewhere. 85 In PAC experiments, there are different routes for introducing radioactive nuclei as a diluted impurity in systems such as nanoparticles, thin films, or bulk: by implantation, 86 by thermal diffusion, 87 during melting or synthesis, 88,89 and by a nuclear reaction during irradiation of the sample. 90,91 In this work, the probe nuclei were inserted through the addition of a small volume of radioactive InCl 3 during the synthesis of nanoparticles.…”

“…In PAC experiments, there are different routes for introducing radioactive nuclei as a diluted impurity in systems such as nanoparticles, thin films, or bulk: by implantation, by thermal diffusion, during melting or synthesis, , and by a nuclear reaction during irradiation of the sample. , In this work, the probe nuclei were inserted through the addition of a small volume of radioactive InCl 3 during the synthesis of nanoparticles. Moreover, in order to obtain comparative parameters, we tried to investigate how the probe nucleus would behave in a Ni-fcc environment.…”

Cobalt Doping Effects in Zinc Oxide: A Combined Experimental and Ab Initio Approach

“…Figure S3: Calculated projected DOS of the Zn-3d states and O-2p states for ZnO UC. References [18,[62][63][64] are cited in the Supplementary Materials.…”

Incorporation of Cd-Doping in SnO2

“…On the other hand, the other fraction was also assigned to the cation-site, but this was done so in a charge state of q = +1. More recently, a study was published that combined the dynamic and static quadrupole interactions, and this was called an on-off model [17]. The measurements were complemented with ab-initio calculations.…”