We confirm the recent prediction that interstitial protium may act as a shallow donor in zinc oxide, by direct spectroscopic observation of its muonium counterpart. On implantation into ZnO, positive muons--chemically analogous to protons this context--form paramagnetic centers below about 40 K. The muon-electron contact hyperfine interaction, well temperature and activation energy for ionization, imply level. Similar results cadmium chalcogenides suggest such states are generic II-VI...

Muonium, and by analogy hydrogen, is shown to form a shallow-donor state in ${\text{In}}_{2}{\text{O}}_{3}$ ${\text{SnO}}_{2}$. The paramagnetic charge stable below $\ensuremath{\sim}50\text{ }\text{K}$ $\ensuremath{\sim}30\text{ ${\text{SnO}}_{2}$ which, coupled with its extremely small effective hyperfine splitting both cases, allows identification as the state. This has important implications for controversial issue of origins conductivity transparent conducting oxides.

Following the prediction and confirmation that interstitial hydrogen forms shallow donors in zinc oxide, inducing electronic conductivity, question arises as to whether it could do so other oxides, not least those under consideration thin-film insulators or high-permittivity gate dielectrics. We have screened a wide selection of binary oxides for this behaviour, therefore, using muonium an accessible experimental model hydrogen. New examples shallow-donor states are required n-type doping...

Abstract This work presents a methodology to optimize well completions in complex carbonate oil rim offshore characterized by heterogeneous plays with highly variable viscosity under strong aquifer and overlying gas condensate reservoir. Maximizing sustainable production was the prime objective while minimizing honoring water constraints. Integrating multizone electric interval control valves (eICVs) continuous hoke dynamic modeling enabled determining optimal depth, length, strategy. A...

Experimental data on shallow donor muonium states in the $\mathrm{II}\mathrm{\ensuremath{-}}\mathrm{VI}$ semiconductor compounds CdS, CdSe, CdTe, and ZnO are presented. These characterized by very weak hyperfine interactions amounting to approximately ${10}^{\ensuremath{-}4}$ of free-atom value, levels with binding energies comparable those calculated hydrogenic model centers. The discussed terms a generalizing knowledge hydrogen tetrahedrally bonded semiconductors. Within this state is...

A new type of muonium defect center has been observed in undoped CdS below 20 K. The hyperfine interaction amounts only to approximately ${10}^{\ensuremath{-}4}$ the vacuum value, and is shown have axial symmetry along Cd-S bond direction. Results suggest that muon close sulfur antibonding site paramagnetic electron density distributed over a large volume. In contrast behavior other semiconductors, forms shallow CdS. By implication, analog isolated hydrogen impurity atoms act as electrically...

A shallow-to-deep instability of hydrogen defect centres in narrow-gap oxide semiconductors is revealed by a study the electronic structure and electrical activity their muonium counterparts, methodology that we term 'muonics'. In CdO, Ag2O Cu2O, paramagnetic show varying degrees delocalization singly occupied orbital, hyperfine constants spanning 4 orders magnitude. PbO RuO2, on other hand, only electronically diamagnetic muon states, mimicking those interstitial protons. Muonium CdO shows...

The incorporation of interstitial hydrogen in yttria was studied by means ab initio calculations based on density-functional theory (DFT) and muonium spin polarization spectroscopy ($\ensuremath{\mu}$SR). calculations, a semilocal functional within the GGA-PBE hybrid functional, uncovered multiple geometrical configurations for neutral, H${}^{0}$, negatively charged, H${}^{\ensuremath{-}}$, states hydrogen, thus demonstrating existence metastable minimum-energy sites. It observed that...

Muonium is like hydrogen, but with a positively charged muon instead of proton at the center. Observing spin rotation in single crystal TiO${}_{2}$, and comparing to existing data for authors demonstrate that defect configuration electronic structure are same both. This provides important support research which uses muons as substitute hydrogen semiconductors.

The electronic structure of hydrogen impurity in ${\mathrm{Lu}}_{2}{\mathrm{O}}_{3}$ was studied by first-principles calculations and muonium spectroscopy. computational scheme based on two methods which are well suited to treat defect $f$-electron systems: first, a semilocal functional conventional density-functional theory (DFT) secondly $\text{DFT}+U$ approach accounts for the on-site correlation $4f$ electrons via an effective Hubbard-type interaction. Three different types stable...

We present a systematic study of isolated hydrogen in diverse forms ${\mathrm{ZrO}}_{2}$ (zirconia), both undoped and stabilized the cubic phase by additions transition-metal oxides $({\mathrm{Y}}_{2}{\mathrm{O}}_{3},{\mathrm{Sc}}_{2}{\mathrm{O}}_{3}$, MgO, CaO). Hydrogen is modeled using muonium as pseudoisotope muon-spin spectroscopy experiments. The muon also supplemented with first-principles calculations states scandia-stabilized zirconia conventional density-functional theory (DFT)...

Thin films and $p\ensuremath{-}n$ junctions for solar cells based on the absorber materials $\mathrm{Cu}(\mathrm{In},\mathrm{G}\mathrm{a}){\mathrm{Se}}_{2}$ ${\mathrm{Cu}}_{2}{\mathrm{ZnSnS}}_{4}$ were investigated as a function of depth using implanted low energy muons. The most significant result is clear decrease formation probability ${\mathrm{Mu}}^{+}$ state at heterojunction interface well surface film. This reduction attributed to reduced bonding reaction muon in defect layer its...

We present a systematic study of isolated hydrogen in $\ensuremath{\alpha}$-TeO${}_{2}$ (paratellurite) by means muon-spin spectroscopy measurements complemented ab initio calculations based on density-functional theory (DFT). The observable metastable states accessible the muon implantation allowed us to probe both donor and acceptor configurations hydrogen, as well follow their dynamics. A shallow state with an ionization energy 6 meV deep are proposed, together atomic-level associated...

Features observed below 300 K in muon-spin rotation and resonance measurements on low-concentration $n$-type ZnSe ZnS samples are interpreted as electron capture by muonium to form ${\text{Mu}}^{\ensuremath{-}}({\ensuremath{\mu}}^{+}{e}^{\ensuremath{-}}{e}^{\ensuremath{-}})$, the analog of negatively charged hydrogen ${\text{H}}^{\ensuremath{-}}$, subsequent emission an from ${\text{Mu}}^{\ensuremath{-}}$ conduction band. In this model, step yields binding energy for second place acceptor...

In muon-spin-rotation experiments, positive muons are implanted in the material and come to rest unrelaxed host lattice. The formation of final configuration requires a lattice relaxation which does not occur instantly. present paper is concerned with transition from initial stopping state muon configuration. We identify often observed fast relaxing signal experiments (e.g., several oxides studied recently) this conversion process. This paramagnetic small hyperfine interaction (in order MHz)...

High-precision spectroscopic information is obtained on the muonium states in ZnSe by high-field transverse $\ensuremath{\mu}\mathrm{SR}$ measurements. At low temperatures, two ${\mathrm{Mu}}_{I}$ and ${\mathrm{Mu}}_{II}$ are observed with isotropic hyperfine parameters of ${\mathrm{A}}_{I}=3283.63\ifmmode\pm\else\textpm\fi{}0.51\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ ${\mathrm{A}}_{II}=3454.26\ifmmode\pm\else\textpm\fi{}0.02\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$ (74% 77% vacuum value,...

The atomistic and electronic structures of isolated hydrogen states in BeO were studied by ab initio calculations muonium spectroscopy (SR). Whereas standard density-functional theory with a semi-local GGA functional led to detailed probing all possible minimum-energy configurations further the hybrid HSE06 provided improved properties avoiding band-gap self-interaction errors. Similarly earlier findings for other wide-gap alkaline-earth oxide, MgO, is also predicted be an amphoteric defect...

Implanted positive muons with low energies (in the range 1–30 keV) are extremely useful local probes in study of thin films and multi-layer structures. The average muon stopping depth, typically order tens nanometers, is a function implantation energy density material, but extends over broad region, which also nanometers. Therefore, an adequate simulation procedure required to extract depth dependence experimental parameters. Here, we present method depth-resolved information from parameters...

The muonium states mimicking interstitial hydrogen in ZnO and HgO are compared. Whereas a theoretically predicted shallow donor state is confirmed, we find considerably deeper state. respective ionization temperatures around 40 K 150 the energies 19±1 136±3 meV, deduced from temperature dependence of µSR (muon spin-rotation) signal amplitudes. spectra provide comprehensive characterization undissociated paramagnetic states: hyperfine parameters, which measure electron spin density on near...

In muon spin rotation experiments, the diamagnetic fraction observed at low temperatures is a consequence of interaction with lattice during incorporation process and depends on properties material. An increase in decreasing temperature some cases, which we attribute to thermal spike end trajectory. The due energy liberated not only stopping but also as stress release when electron bound an unrelaxed configuration jumps neighboring site. magnitude time extension this effect are more...

The local binding and migration behavior of the proton defect in cubic yttria-stabilized zirconia (YSZ) is studied by first-principles calculations muon-spin spectroscopy (μSR) measurements. are based on density-functional theory (DFT) supplemented with a hybrid-functional approach embedded quasi-random supercells 10.3 mol% yttria content, where yttrium–zirconium substitutional defects charge compensated oxygen vacancies. Representative pathways for comprising both transfer bond...

Cu(In,Ga)Se2 (CIGS) and Cu2ZnSnS4 (CZTS) are potential absorber materials for solar cell applications. We report an investigation of these using muon spin spectroscopy. In experiments, positive muons produced at accelerator facilities (here the ISIS Facility, Rutherford Appleton Laboratory, U.K.) implanted into material come to rest interstitial sites in host lattice. The is a sensitive local probe study properties on atomistic level. An advantage method that interface can be studied by...