Dominant Proton Research Articles

Integrated Experiment-Theory Framework for Studying Mass Transport Effects in Electrochemical CO2 Reduction on Copper

Electrochemical carbon dioxide reduction (eCO2R) has emerged as a promising approach to produce high-value fuels and chemicals using renewable energy sources. In particular, Cu catalysts can convert CO2 to a wide range of hydrocarbon and oxygenate products, including CO, formate, ethanol and ethylene. However, the activity and selectivity of eCO2R is highly dependent on mass transport and the corresponding reaction microenvironment present under operating conditions. In this talk, we present an integrated framework that combines experiments with computational fluid dynamics (CFD) and density functional theory (DFT) based microkinetic modeling to predict the effect of varying mass transport on eCO2R in a custom-designed flow cell. The flow cell is designed with multiple electrolyte jets impinging onto the electrocatalyst surface for rapid and homogeneous reactant transport. We first demonstrate the effect of mass transport in a flow cell architecture by controlling the flow rate of CO2-saturated 0.1 M KHCO3 to a Cu electrocatalyst. Significant increases in the production rates of formate and CO are observed with increasing flow rate, as well as an enhancement in multi-carbon products at high overpotentials. Increasing flow rate promotes hydrogen evolution at low overpotentials but has little effect at large overpotentials, suggesting a transition from HCO3 - to water as the dominant proton donor with increasing overpotential. CFD simulations are employed to model the distribution of boundary layer thicknesses within the flow cell, which subsequently set the boundary conditions for the coupled 1D transport-microkinetic model. The calculated boundary layer thickness values are corroborated by experimentally measured transport-limited currents. Our model successfully predicts experimentally observed trends in selectivity with mass transport, such as an increase in the production of ethylene and ethanol at high flow rates due to enhanced CO2 transport. The slight suppression of hydrogen reduction at higher flow rates due to an increase in *CO coverage is also predicted and supported by experimental results. This work demonstrates the importance of incorporating transport processes in the CFD-DFT coupled modeling of device performance for electrochemical CO2 reduction.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL release number: LLNL-ABS-857566.

Semiconductor Heterostructure (SrFe0.3TiO3-ZnO) Electrolyte with High Proton Conductivity for Low-Temperature Ceramic Electrochemical Cells.

In recent years, ceramic cells based on high proton conductivity have attracted much attention and can be employed for hydrogen production and electricity generation, especially at low temperatures. Nevertheless, attaining a high power output and durability is challenging, especially at low operational temperatures. In this regard, we design semiconductor heterostructure SFT-ZnO (SrFe0.3TiO3-ZnO) materials to function as an electrolyte for fuel cell and electrolysis applications. Using this approach, the functional semiconductor heterostructure can deliver a better power output and high ionic and proton conductivity at low operational temperatures. The prepared cell in fuel cell mode has demonstrated excellent performance of 700 mW cm-2 and proton performance of 540 mW cm-2 at the low temperature of 520 °C, suggesting dominant proton conduction. Further, the prepared cell delivers exceptional current densities of 1.18 and 0.38 A cm-2 (at 1.6 and 1.3 V, respectively) at 520 °C in the electrolysis mode. Our electrochemical cell is stable in fuel and electrolysis mode at a low temperature of 500 °C.

Proton-Coupled Electron Transfer upon Oxidation of Tyrosine in a De Novo Protein: Analysis of Proton Acceptor Candidates.

Redox-active residues, such as tyrosine and tryptophan, play important roles in a wide range of biological processes. The α3Y de novo protein, which is composed of three α helices and a tyrosine residue Y32, provides a platform for investigating the redox properties of tyrosine in a well-defined protein environment. Herein, the proton-coupled electron transfer (PCET) reaction that occurs upon oxidation of tyrosine in this model protein by a ruthenium photosensitizer is studied by using a vibronically nonadiabatic PCET theory that includes hydrogen tunneling and excited vibronic states. The input quantities to the analytical nonadiabatic rate constant expression, such as the diabatic proton potential energy curves and associated proton vibrational wave functions, reorganization energy, and proton donor-acceptor distribution functions, are obtained from density functional theory calculations on model systems and molecular dynamics simulations of the solvated α3Y protein. Two possible proton acceptors, namely, water or a glutamate residue in the protein scaffold, are explored. The PCET rate constant is greater when glutamate is the proton acceptor, mainly due to the more favorable driving force and shorter equilibrium proton donor-acceptor distance, although contributions from excited vibronic states mitigate these effects. Nevertheless, water could be the dominant proton acceptor if its equilibrium constant associated with hydrogen bond formation is significantly greater than that for glutamate. Although these calculations do not definitively identify the proton acceptor for this PCET reaction, they elucidate the conditions under which each proton acceptor can be favored. These insights have implications for tyrosine-based PCET in a wide variety of biochemical processes.

Local Structure and Mixed Proton-Hole Conduction in Y and Al-Doped BaZrO3

Enhancing proton-hole mixed conduction is one of the promising methods to improve the cathode performance of proton-conducting fuel cells. In this study, Al-doping is conducted to enhance the hole conduction in Y-doped BaZrO3. The relationship between the defect structure around Al and the electrical conductivity is investigated. 27Al NMR results indicated the formation of more than one oxygen vacancy around Al and the clustering of the acceptors. The electrical conductivity shows dominant proton conduction below 600ºC while other charge carriers, such as oxygen vacancies and electron holes, dominate at 800ºC. The Al-doping affects the formation of the defects but shows negligible influence on the dominant charge carriers at lower temperatures.

Transport Properties of Intergrowth Structures Ba5In2Al2ZrO13 and Ba7In6Al2O19

The development of solid oxide fuel cells operating at medium temperatures (500–700 °C and even lower) requires the search for proton conductors based on complex oxides that would have a wide range of required properties. This task stimulates the search for new promising phases with proton conductivity. The new hexagonal perovskite-related compound Ba7In6Al2O19 was synthesized by the solid-state method. The phase was characterized by powder X-ray diffraction, thermogravimetric analysis, FT-IR spectroscopy, and impedance spectroscopy (in a wide range of temperatures, and partial pressures of oxygen at various atmospheric humidities). The investigated phase had a hexagonal structure with a space group of P63/mmc; the lattice parameters for Ba7In6Al2O19 are a = 5.921(2) Å, c = 37.717(4) Å. The phase is capable of reversible hydration and incorporates up to 0.15 mol H2O. IR-data confirmed that protons in the hydrated compound are presented in the form of OH–-groups. Electrical conductivity data showed that the sample exhibited dominant oxygen-ion conductivity below 500 °C in dry air and dominant proton conductivity below 600 °C in wet air.

Energy Partition at Collisionless Supercritical Quasi‐Perpendicular Shocks

AbstractCollisionless shocks in astrophysical plasmas are important thermalizers, converting some of the incident flow energy into thermal energy, and non‐thermalizers, partitioning that energy in unequal ways to different particle species, subpopulations thereof, and field components. This partition problem, or equivalently the shock equation of state, lies at the heart of shock physics. Here, we employ systematically a framework to capture all the incident and downstream energy fluxes at two example traversals of the Earth's bow shock by the Magnetospheric Multiscale Mission. Here and traditionally, such data has to be augmented by information from other spacecraft, for example, to provide more accurate measurements of the cold solar wind beam. With some care and fortuitous choices, the total energy flux is conserved, including instantaneous measurements through the shock layer. The dominant incident proton ram energy is converted primarily into downstream proton enthalpy flux, the majority of which is actually carried by a small fraction of suprathermal protons. Fluctuations include both real and instrumental effects. Separating these, resolving the solar wind beam, and other considerations point the way to a dedicated mission to solve this energy partition problem across a full range of plasma and shock conditions.

The Plant V-ATPase.

V-ATPase is the dominant proton pump in plant cells. It contributes to cytosolic pH homeostasis and energizes transport processes across endomembranes of the secretory pathway. Its localization in the trans Golgi network/early endosomes is essential for vesicle transport, for instance for the delivery of cell wall components. Furthermore, it is crucial for response to abiotic and biotic stresses. The V-ATPase’s rather complex structure and multiple subunit isoforms enable high structural flexibility with respect to requirements for different organs, developmental stages, and organelles. This complexity further demands a sophisticated assembly machinery and transport routes in cells, a process that is still not fully understood. Regulation of V-ATPase is a target of phosphorylation and redox-modifications but also involves interactions with regulatory proteins like 14-3-3 proteins and the lipid environment. Regulation by reversible assembly, as reported for yeast and the mammalian enzyme, has not be proven in plants but seems to be absent in autotrophic cells. Addressing the regulation of V-ATPase is a promising approach to adjust its activity for improved stress resistance or higher crop yield.

Proton and Oxygen-Ion Conductivities of Hexagonal Perovskite Ba5In2Al2ZrO13.

The hexagonal perovskite Ba5In2Al2ZrO13 and In3+-doped phase Ba5In2.1Al2Zr0.9O12.95 were prepared by the solid-state synthesis method. The introduction of indium in the Zr-sublattice was accompanied by an increase in the unit cell parameters: a = 5.967 Å, c = 24.006 Å vs. a = 5.970 Å, c = 24.011 Å for doped phase (space group of P63/mmc). Both phases were capable of incorporating water from the gas phase. The ability of water incorporation was due to the presence of oxygen deficient blocks in the structure, and due to the introduction of oxygen vacancies during doping. According to thermogravimetric (TG) measurements the compositions of the hydrated samples corresponded to Ba5In2Al2ZrO12.7(OH)0.6 and Ba5In2.1Al2Zr0.9O12.54(OH)0.82. The presence of different types of OH−-groups in the structure, which participate in different hydrogen bonds, was confirmed by infrared (IR) investigations. The measurements of bulk conductivity by the impedance spectroscopy method showed that In3+-doping led to an increase in conductivity by 0.5 order of magnitude in wet air (pH2O = 1.92·10−2 atm); in this case, the activation energies decreased from 0.27 to 0.19 eV. The conductivity−pO2 measurements showed that both the phases were dominant proton conductors at T < 500 °C in wet conditions. The composition Ba5In2.1Al2Zr0.9O12.95 exhibited a proton conductivity ~10−4 S·cm−1 at 500 °C. The analysis of partial (O2−, H+, h•) conductivities of the investigated phases has been carried out. Both phases in dry air (pH2O = 3.5·10−5 atm) showed a mixed (oxygen-ion and hole) type of conductivity. The obtained results indicated that the investigated phases of Ba5In2Al2ZrO13 and Ba5In2.1Al2Zr0.9O12.95 might be promising proton-conducting oxides in the future applications in electrochemical devices, such as solid oxide fuel cells. Further modification of the composition and search for the optimal dopant concentrations can improve the H+-conductivity.

Unveiling the Reversibility and Stability Origin of the Aqueous V2 O5 -Zn Batteries with a ZnCl2 "Water-in-Salt" Electrolyte.

Aqueous V2O5–Zn batteries, an alternative chemistry format that is inherently safer to operate than lithium‐based batteries, illuminates the low‐cost deployment of the stationary energy storage devices. However, the cathode structure collapse caused by H2O co‐insertion in aqueous solution dramatically deteriorates the electrochemical performance and hampers the operation reliability of V2O5–Zn batteries. The real‐time phase tracking and the density functional theory (DFT) calculation prove the high energy barrier that inhibits the Zn2+ diffusion into the bulk V2O5, instead the ZnCl2 “water‐in‐salt electrolyte” (WiSE) can enable the dominant proton insertion with negligible lattice strain or particle fragment. Thus, ZnCl2 WiSE enables the enhanced reversibility and extended shelf life of the V2O5–Zn battery upon the high temperature storage. The improved electrochemical performance also benefits by the inhibition of vanadium cation dissolution, enlarged voltage window, as well as the suppression of the Zn dendrite protrusion. This study comprehensively elucidates the pivotal role of a concentrated ZnCl2 electrolyte to stabilize the aqueous batteries at both the static storage and dynamic operation scenarios.

Plant Proton Pumps and Cytosolic pH-Homeostasis.

Proton pumps create a proton motif force and thus, energize secondary active transport at the plasma nmembrane and endomembranes of the secretory pathway. In the plant cell, the dominant proton pumps are the plasma membrane ATPase, the vacuolar pyrophosphatase (V-PPase), and the vacuolar-type ATPase (V-ATPase). All these pumps act on the cytosolic pH by pumping protons into the lumen of compartments or into the apoplast. To maintain the typical pH and thus, the functionality of the cytosol, the activity of the pumps needs to be coordinated and adjusted to the actual needs. The cellular toolbox for a coordinated regulation comprises 14-3-3 proteins, phosphorylation events, ion concentrations, and redox-conditions. This review combines the knowledge on regulation of the different proton pumps and highlights possible coordination mechanisms.

Neutrino signal dependence on gamma-ray burst emission mechanism

Long duration gamma-ray bursts (GRBs) are among the least understood astrophysical transients powering the high-energy universe. To date, various mechanisms have been proposed to explain the observed electromagnetic GRB emission. In this work, we show that, although different jet models may be equally successful in fitting the observed electromagnetic spectral energy distributions, the neutrino production strongly depends on the adopted emission and dissipation model. To this purpose, we compute the neutrino production for a benchmark high-luminosity GRB in the internal shock model, including a dissipative photosphere as well as three emission components, in the jet model invoking internal-collision-induced magnetic reconnection and turbulence (ICMART), in the case of a magnetic jet with gradual dissipation, and in a jet with dominant proton synchrotron radiation. We find that the expected neutrino fluence can vary up to three orders of magnitude in amplitude and peak at energies ranging from 104 to 108 GeV. For our benchmark input parameters, none of the explored GRB models is excluded by the targeted searches carried out by the IceCube and ANTARES Collaborations. However, our work highlights the potential of high-energy neutrinos of pinpointing the underlying GRB emission mechanism and the importance of relying on different jet models for unbiased stacking searches.

Poly(benzimidazole)/poly(vinylphosphonic acid) blend membranes with enhanced performance for high temperature polymer electrolyte membrane fuel cells

PBI:PVPA (Poly(benzimidazole):poly(vinylphosphonic acid)) polymer electrolyte membranes were fabricated with several molar ratios and number-average molecular weights (M¯n) of PVPA. Inter-polymer interactions and cross-section morphology of membranes were analyzed using FT-IR and scanning electron microscopy, respectively. Water uptake, proton conductivity, and methanol permeability of the membranes were characterized at several operating conditions. In addition, the influence of doping level of phosphoric acid (H3PO4) on the membranes proton conductivity was investigated. The membranes proton conductivities were enhanced with PVPA molar ratio and M¯n. The highest proton conductivity at 150 °C, 79.6 mS.cm−1, was obtained for H3PO4-doped PBI:PVPA membrane containing PVPA with M¯n of 42,000 g.mol−1, PBI:PVPA molar ratio of 1:1 and H3PO4 doping level of 15.2. Proton hopping between PBI and PVPA was found to be the most dominant proton transport mechanism through the PBI:PVPA membranes, especially at anhydrous state. Finally, the results suggest that these membranes are promising candidates for high-temperature proton exchange membrane fuel cell applications.

Low-energy probes of no-scale SU(5) super-GUTs

We explore the possible values of the mu rightarrow e gamma branching ratio, text {BR}(mu rightarrow egamma ), and the electron dipole moment (eEDM), d_e, in no-scale SU(5) super-GUT models with the boundary conditions that soft supersymmetry-breaking matter scalar masses vanish at some high input scale, M_mathrm{in}, above the GUT scale, M_{mathrm{GUT}}. We take into account the constraints from the cosmological cold dark matter density, Omega _{CDM} h^2, the Higgs mass, M_h, and the experimental lower limit on the lifetime for p rightarrow K^+ bar{nu }, the dominant proton decay mode in these super-GUT models. Reconciling this limit with Omega _{CDM} h^2 and M_h requires the Higgs field responsible for the charge-2/3 quark masses to be twisted, and possibly also that responsible for the charge-1/3 and charged-lepton masses, with model-dependent soft supersymmetry-breaking masses. We consider six possible models for the super-GUT initial conditions, and two possible choices for quark flavor mixing, contrasting their predictions for proton decay with versions of the models in which mixing effects are neglected. We find that tau left( prightarrow K^+ bar{nu }right) may be accessible to the upcoming Hyper-Kamiokande experiment, whereas all the models predict text {BR}(mu rightarrow egamma ) and d_e below the current and prospective future experimental sensitivities or both flavor choices, when the dark matter density, Higgs mass and current proton decay constraints are taken into account. However, there are limited regions with one of the flavor choices in two of the models where mu rightarrow e conversion on a heavy nucleus may be observable in the future. Our results indicate that there is no supersymmetric flavor problem in the class of no-scale models we consider.

Investigating the origin of pH-sensitive magnetization transfer ratio asymmetry MRI contrast during the acute stroke: Correction of T1 change reveals the dominant amide proton transfer MRI signal.

Amide proton transfer (APT) MRI is promising to serve as a surrogate metabolic imaging biomarker of acute stroke. Although the magnetization transfer ratio asymmetry (MTRasym ) has been used commonly, the origin of pH-weighted MRI effect remains an area of investigation, including contributions from APT, semisolid MT contrast asymmetry, and nuclear Overhauser enhancement effects. Our study aimed to determine the origin of pH-weighted MTRasym contrast following acute stroke. Multiparametric MRI, including T1 , T2 , diffusion and Z-spectrum, were performed in rats after middle cerebral artery occlusion. We analyzed the conventional Z-spectrum and the apparent exchange spectrum , being the difference between the relaxation-scaled inverse Z-spectrum and the intrinsic spinlock relaxation rate . The ischemia-induced change was calculated as the spectral difference between the diffusion lesion and the contralateral normal area. The conventional Z-spectrum signal change at -3.5 ppm dominates that at +3.5 ppm (-1.16 ± 0.39% vs. 0.76 ± 0.26%, P < .01) following acute stroke. In comparison, the magnitude of ΔRex change at 3.5 ppm becomes significantly larger than that at -3.5 ppm (-2.80 ± 0.40% vs. -0.94 ± 0.80%, P < .001), with their SNR being 7.0 and 1.2, respectively. We extended the magnetization transfer and relaxation normalized APT concept to the apparent exchange-dependent relaxation image, documenting an enhanced pH contrast between the ischemic lesion and the intact tissue, over that of MTRasym . Our study shows that after the relaxation-effect correction, the APT effect is the dominant contributing factor to pH-weighted MTRasym following acute stroke.

Incorporation and Conduction of Protons in Ca, Sr, Ba-Doped BaLaInO4 with Ruddlesden-Popper Structure.

The new phases BaLa0.9M0.1InO3.95 (M = Ca2+, Sr2+, Ba2+) with a Ruddlesden-Popper structure were obtained. It was established that all investigated samples were capable for the water uptake from the gas phase. The ability of water incorporation was due to not only by the presence of oxygen vacancies, but also due to the presence of La-O blocks in the structure. The degree of hydration of the samples was much higher than the concentration of oxygen vacancies and the composition of the samples appear to be BaLaInO3.42(OH)1.16, BaLa0.9Ca0.1InO3.25(OH)1.4, BaLa0.9Sr0.1InO3.03(OH)1.84, BaLa0.9Ba0.1InO2.9(OH)2.1. The degree of hydration increased with an increase in the size of the dopant, i.e., with an increase in the size of the salt blocks. It was proven that doping led to the increase in the oxygen ionic conductivity. The conductivities for doped samples BaLa0.9M0.1InO3.95 were higher than for undoped composition BaLaInO4 at ~1.5 order of magnitude. The increase in the conductivity was mainly attributed to the increase of the carrier concentration as a result of the formation of oxygen vacancies during doping. The proton conductivities of doped samples increased in the order Ca2+–Sr2+–Ba2+ due to an increase in the concentration of protons. It was established that all doped samples demonstrated the dominant proton transport below 450 °C.

Predictions for the First Parker Solar Probe Encounter

Abstract We examine Alfvén Wave Solar atmosphere Model (AWSoM) predictions of the first Parker Solar Probe (PSP) encounter. We focus on the 12 day closest approach centered on the first perihelion. AWSoM allows us to interpret the PSP data in the context of coronal heating via Alfvén wave turbulence. The coronal heating and acceleration is addressed via outward-propagating low-frequency Alfvén waves that are partially reflected by Alfvén speed gradients. The nonlinear interaction of these counter-propagating waves results in a turbulent energy cascade. To apportion the wave dissipation to the electron and anisotropic proton temperatures, we employ the results of the theories of linear wave damping and nonlinear stochastic heating as described by Chandran et al. We find that during the first encounter, PSP was in close proximity to the heliospheric current sheet (HCS) and in the slow wind. PSP crossed the HCS two times, at 2018 November 3 UT 01:02 and 2018 November 8 UT 19:09, with perihelion occurring on the south of side of the HCS. We predict the plasma state along the PSP trajectory, which shows a dominant proton parallel temperature causing the plasma to be firehose unstable.

Oxide versus Nonoxide Cathode Materials for Aqueous Zn Batteries: An Insight into the Charge Storage Mechanism and Consequences Thereof

Aqueous Zn-ion batteries, which are being proposed as large-scale energy storage solutions because of their unparalleled safety and cost advantage, are composed of a positive host (cathode) material, a metallic zinc anode, and a mildly acidic aqueous electrolyte (pH ≈ 3-7). Typically, the charge storage mechanism is believed to be reversible Zn2+ (de)intercalation in the cathode host, with the exception of α-MnO2, for which multiple vastly different and contradicting mechanisms have been proposed. However, our present study, combining electrochemical, operando X-ray diffraction, electron microscopy in conjunction with energy-dispersive X-ray spectroscopy, and in situ pH evolution analyses on two oxide hosts-tunneled α-MnO2 and layered V3O7·H2O vis-à-vis two nonoxide hosts-layered VS2 and tunneled Zn3[Fe(CN)6]2, suggests that oxides and nonoxides follow two dissimilar charge storage mechanisms. While the oxides behave as dominant proton intercalation materials, the nonoxides undergo exclusive zinc intercalation. Stabilization of H+ on the hydroxyl-terminated oxide surface is revealed to facilitate the proton intercalation by a preliminary molecular dynamics simulation study. Proton intercalation for both oxides leads to the precipitation of layered double hydroxide (LDH)-Zn4SO4(OH)6·5H2O with a ZnSO4/H2O electrolyte and a triflate anion (CF3SO3-)-based LDH with a Zn(SO3CF3)2/H2O electrolyte-on the electrode surface. The LDH precipitation buffers the pH of the electrolytes to a mildly acidic value, sustaining the proton intercalation to deliver large specific capacities for the oxides. Moreover, we also show that the stability of the LDH precipitate is crucial for the rechargeability of the oxide cathodes, revealing a critical link between the charge storage mechanism and the performance of the oxide hosts in aqueous zinc batteries.

Particle content, radio-galaxy morphology, and jet power: all radio-loud AGN are not equal

Ongoing and future radio surveys aim to trace the evolution of black hole growth and feedback from active galactic nuclei (AGN) throughout cosmic time; however, there remain major uncertainties in translating radio luminosity functions into a reliable assessment of the energy input as a function of galaxy and/or dark matter halo mass. A crucial and long-standing problem is the composition of the radio-lobe plasma that traces AGN jet activity. In this paper, we carry out a systematic comparison of the plasma conditions in Fanaroff & Riley class I and II radio galaxies to demonstrate conclusively that their internal composition is systematically different. This difference is best explained by the presence of an energetically dominant proton population in the FRI, but not the FRII radio galaxies. We show that, as expected from this systematic difference in particle content, radio morphology also affects the jet-power/radio-luminosity relationship, with FRII radio galaxies having a significantly lower ratio of jet power to radio luminosity than the FRI cluster radio sources used to derive jet-power scaling relations via X-ray cavity measurements. Finally we also demonstrate conclusively that lobe composition is unconnected to accretion mode (optical excitation class): the internal conditions of low- and high-excitation FRII radio lobes are indistinguishable. We conclude that inferences of population-wide AGN impact require careful assessment of the contribution of different jet sub-classes, particularly given the increased diversity of jet evolutionary states expected to be present in deep, low-frequency radio surveys such as the LOFAR Two-Metre Sky Survey.

Conversion-electron spectroscopy and gamma-gamma angular correlation measurements in 116Sn

The 116Sn nucleus was studied via the $\beta^{-}$ decay of 116In utilizing the $8\pi$ spectrometer and its auxiliary detectors at TRIUMF-ISAC. The resulting K-shell conversion coefficients, K/L ratios, and multipole mixing ratios are presented. The $2_{3}^{+} \rightarrow 2_{1}^{+} 931$ keV and $ 2_{2}^{+} \rightarrow 2_{1}^{+} 819$ keV transition mixing ratios were re-measured and found to be $ \delta = +1.8_{-0.5}^{+0.7}$ and $ -1.83(8)$ , respectively. Newly measured mixing ratios for transitions among the low-lying $ I^{\pi} = 4^{+}$ states in 116Sn, when combined with $\gamma$ -ray intensity data, suggest that the 2529 keV $4_{2}^{+}$ state possesses a neutron broken-pair admixture in addition to its dominant proton 2p-2h component.

Proton transport in perovskites Ba2InMO6 (M = Nb, Ta)

The reasons for the appearance of proton conductivity in the complex oxide Ba2InMO6 phases (M = Nb, Ta) with a formally complete oxygen sublattice were determined. The formation of oxygen vacancies in the structure as a result of the violation of stoichiometry causes the introduction of water, the amount of which does not exceed 0.02 mol per formula unit of the composition. The appearance of proton defects even in low concentrations provides the dominant proton transfer below 500°C.