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Alex B. Martinson

Publications and source records attributed to Alex B. Martinson.

2 recordsLinked to original sources

Computational study of indium oxide photoelectrodes

Using a combination of first principles molecular dynamics simulations (FPMD) and electronic structure calculations, we characterize the atomistic structure and vibrational properties of a photocatalytic surface of In$_2$O$_3$, a promising photoelectrode for the production of hydrogen peroxide. We then investigate the surface in contact with water and show that the electronic states of In$_2$O$_3$ are appropriately positioned in energy to facilitate the two-electron water oxidation reaction (WOR) over the competing four-electron oxygen evolution reaction. We further propose that the use of strained thin films interfaced with water is beneficial in decreasing the optical gap of In$_2$O$_3$ and thus utilizing a wider portion of the solar spectrum for the WOR.

cond-mat.mtrl-sci

Superconductivity in the dilute single band limit in reduced Strontium Titanate

We report on superconductivity in single crystals of SrTiO$_{3-δ}$ with carrier densities $\textit{n} < 1.4 \times10^{18}cm^{-3}$, where only a single band is occupied. For all samples in this regime, the resistive transition occurs at $T_{c} \approx 65 \pm 25 \ mK$. We observe a zero resistance state for $\textit{n}$ as low as $1.03 \times10^{17}cm^{-3}$, and a partial resistive transition for $\textit{n} = 3.85 \times10^{16}cm^{-3}$. We observe low critical current densities, relatively high and isotropic upper critical fields, and an absence of diamagnetic screening in these samples. Our findings suggest an inhomogeneous superconducting state, embedded within a homogeneous high-mobility 3-dimensional electron gas. $T_{c}$ does not vary appreciably when $\textit{n}$ changes by more than an order of magnitude, inconsistent with conventional superconductivity.

cond-mat.supr-con