Thin MgO Research Articles

Atomic-Scale Mechanism of Enhanced Electron-Phonon Coupling at the Interface of MgB2 Thin Films.

In conventional Bardeen-Cooper-Schrieffer (BCS) superconductors, electron-phonon coupling is the fundamental mechanism of superconductivity. For instance, the superconductivity of magnesium diboride (MgB2) comes from the coupling between E2g modes (in-plane boron-boron bond vibrations) and self-doped charge carriers. In thin films and ceramics of BCS superconductors, interfaces with discontinuous chemical bonds may alter the local electron-phonon coupling. However, such effects remain largely unexplored. Here, we investigate the heterointerface of the MgB2 film on the SiC substrate at the atomic scale using electron microscopy and spectroscopy. We detect the presence of a thin MgO layer with a thickness of ∼1 nm between MgB2 and SiC. Atomic-level electron energy loss spectra (EELS) show MgB2-E2g mode splitting and softening near the MgB2/MgO interface, which enhances electron-phonon coupling at the interface. Our findings highlight the potential of interface engineering to enhance superconductivity via modulating local phonon states and/or electron states.

Impact of the gate work function on the experimental I-V characteristics of MOS solar cells simulated with the Sentaurus TCAD software

In this work, the influence of gate work function on the experimental J-VG characteristics of MOS solar cells was investigated with the aid of the Sentaurus TCAD for 2D numer-ical simulations of TiN/SiOxNy/Si Al/SiOxNy/Si and Al/MgO/Mg/SiOxNy/Si structures aiming at solar cells for en-ergy harvesting applications. The increase of the gate work function led to the increase of the reverse current density as pointed out by the Sentaurus TCAD simulations and by the ex-perimental J-VG characteristics. The work functions of Mg, Al, and un-annealed TiN used in the TCAD simulations were 3.7 eV, 4.1 eV, and 4.4 eV, respectively. It was observed that the onset voltage at 0.5 mA/cm2 in the forward-biasing region was at a lower voltage for TiN (~ - 0.06 V) compared to Al (~ - 0.42 V) and the Al/MgO/Mg stack (~ - 0.47 V). On the other hand, the current density increased steeply in the forward biasing for TiN and Al compared to the Al/ MgO/Mg stack gate and the thin MgO layer between Al and Mg worked as a potential barrier in an opposite direction to the potential barrier of the Mg/Si-OxNy/Si structure, which meant an onset voltage lowering for the Al/MgO/Mg/SiOxNy/Si solar cell. For the Al/MgO/Mg stack, the barrier effect of the MgO layer was fitted as a series re-sistance RS = 100 Ω and an equivalent Al/MgO/Mg work func-tion of 4.15 eV considering a substrate doping NA = 1.2x1016 cm-3 and parallel conductance GP = 0. Also, the experimental JxVG characteristic of the Al/SiOxNy/Si cell was fitted for Al work function of 4.10 eV, a series resistance RS = 100 Ω, a parallel resistance RP = 0.02 Ω (GP = 50 S) and a substrate doping NA = 5.5x1015 cm-3. In this case, the high parallel conductance fitted was attributed to the tunneling through the dielectrics as a pre-dominant effect possibly caused by a high concentration of de-fects in the SiOxNy layer. Finally, the MOS solar cell parameters were relatively lower compared to those of commercial outdoor solar cells, but the power generated by the MOS cells reached the mW range, and the conversion efficiency from light energy into electrical energy was higher (12.7%) than the typical values found for energy-harvesting solar cells.

Highly Transparent and Stable Flexible Electrodes Based on MgO/AgNW Nanocomposites for Transparent Heating Applications

AbstractTransparent electrodes (TE) based on silver nanowire (AgNW) exhibit good physical properties and constitute a promising alternative to transparent conductive oxides due to their low cost, flexibility, and low toxicity. Nevertheless, they suffer from stability issues over harsh conditions, and encapsulation allows to overcome these limitations. Herein, the low‐cost, scalable fabrication and study of transparent electrodes based on sprayed AgNW networks coated with MgO thin films deposited by atmospheric pressure spatial atomic layer deposition (AP‐SALD) at mild deposition temperature (≤220 °C) is reported. Fabrication of MgO thin films by AP‐SALD is reported here for the first time, and their deposition on different substrates is optimized. MgO exhibits a pure phase and conformal growth with a preferential (220) crystalline orientation and a higher growth rate as compared to conventional atomic layer deposition (ALD). Furthermore, thanks to the conformal coating of MgO on AgNW, the obtained nanocomposites exhibit great optical transparency of ≈85% and flexibility while maintaining high stability under thermal and electrical stress. Indeed, this study shows a clear enhancement of the stability of AgNW networks for thin MgO coatings of only a few nanometers thick. Finally, a proof‐of‐concept transparent heater is fabricated to melt a piece of cheese.

Determination on the Metastable Interface Structure of Nb/MgO(100) Interface

The metastable interface structures between Nb thin films and MgO(100) substrate are investigated using first‐principles calculation. Based on the calculation results of interface separation works for 25 interface models, three metastable interfaces and one stable interface are identified. The growth orientations of Nb films in both the metastable and stable interfaces are found to be Nb[110] and Nb[100], respectively, which align with previous experimental findings. This suggests that it is feasible to predict the metastable interfaces in metal/oxide interface systems by calculating interface energy. Additionally, a comparison is conducted between the stable and metastable interfaces. The metastable interface exhibits a lower interface separation work and lower system energy compared to the stable interface. Herein, it is indicated that the interface separation work plays a key role in determining the metastable interface structure of Nb/MgO(100), rather than the total energy of the entire interface system.

Interface structure between Nb thin film and MgO(112) substrate: A first-principles prediction

The crystal orientation of ceramic substrates is an important factor affecting the interface structure of metal/ceramic composite materials. However, there is little information about the interface composed of metal films and ceramic substrates with a high-index plane. In this work, we predicted the interface structure between a Nb film and a MgO(112) substrate by calculating the interface separation works of different interface models by using the first-principles calculation method. The results showed that the preferred growth direction is Nb [120], and that the value of the interface separation work is 0.35 eV/Å2. The lattice mismatch between the film and substrate is less than 3%, implying that a coherent interface type is highly realizable in Nb/MgO(112). Furthermore, we analyzed the interface structures of Nb/MgO(100), Nb/MgO(110), Nb/MgO(111), and Nb/MgO(112) and found that the unique atomic configuration of the MgO substrate is the main factor determining the preferred interface structure of Nb/MgO.

Demonstration of reconfigurable magnetic tunnel diode and giant tunnel magnetoresistance in magnetic tunnel junctions made with spin gapless semiconductor and half-metallic Heusler alloy

Here, we report fabrication of a high quality exchanged biased trilayer magnetic tunnel junction (MTJ) utilizing a magnetron sputtering system. The MTJ is composed of a type-II spin gapless semiconductor (SGS) Ti2CoSi inverse Heusler alloy (used as a lower electrode), a thin MgO layer (used as a tunnel barrier), and a half-metallic ferromagnet (HMF) Co2MnSi Heusler alloy (used as an upper electrode). Spin dependent transport properties reveal that the micro-fabricated MTJ can act as a reconfigurable magnetic tunnel diode, which lets the electric current to flow in either the forward or reverse path relying on the relative alignment of the magnetization direction of the upper and lower magnetic electrodes. A considerably high on/off current ratio (∼103) and a significantly low turn on voltage (VT) of 0.09 V have been achieved at 5 K for both parallel and antiparallel configurations. Another important characteristic shown by our fabricated MTJ is that it exhibits extremely large tunnel magnetoresistance ratios of 892% at 5 K and 197% at room temperature, which brings to light the utmost importance of using the combination of HMF and SGS materials as magnetic electrodes in a tunnel junction for potential applications in modern spintronic devices. All these exceptional features can undoubtedly nominate CMS/MgO/TCS MTJs as a promising candidate to serve as memory or logic elements in next generation ultra-high density magnetoresistive random access memories together with contemporary spin based electronic devices.

Enhancing the Schottky-barrier height by inserting a thin MgO layer between Au and annealed-ZnO

The effects of a thin MgO insertion layer between Au and annealed-ZnO on the Schottky-barrier diodes (SBDs) of Au/annealed-ZnO were studied. The structure of Au/as-deposited ZnO (SBD_A) presents a rather leaky (near ohmic) characteristic owing to the presence of oxygen vacancies on the ZnO surface. After post-annealing of ZnO in air, the Au/annealed-ZnO (SBD_B) exhibits a rectifying behavior as a result of the compensated oxygen vacancies. Upon inserting a MgO film between the Au and annealed-ZnO, the leakage current is significantly reduced by approximately 3-orders of magnitude in the Au/MgO/annealed-ZnO structure (SBD_C), largely enhancing the rectification ratio from 10.3 to 731. This is because the oxygen vacancies are further reduced by the MgO modification of ZnO. The post-ZnO annealing and MgO insertion increased the Schottky-barrier height (SBH) from 0.58 to 0.68 and 1.1 eV in SBD_A, SBD_B, and SBD_C, respectively. Hence, the MgO insertion not only decreases the oxygen vacancies on the ZnO surface, it also increases the SBH. X-ray diffraction, X-ray photoelectron spectroscopy, and band-diagrams were employed to elucidate the mechanisms of the increase in SBH.

Can Y2O3-MgO eutectics be new promising structural and optical ceramics?

The manuscript addresses the solidification of Y2O3-MgO eutectic composites for the first time, and the study of their microstructure, mechanical properties and infrared transmittance. The composites with eutectic composition (20 % vol MgO) have been solidified using the laser floating zone method, at solidification rates between 25 mm/h and 750 mm/h. Their microstructure has been quantified and the conditions for coupled or cellular regime determined. They are dense, with elastic modulus, as determined from nanoindentation tests of around 200 GPa. The highest 3-point flexural strength (256±25 MPa) values and highest infrared optical transmittance has been observed for the material solidified with the finest, still homogeneous microstructure that could be achieved. This microstructure, which is achieved at a solidification rate of 50mm/h, consists of MgO fibers of 600 nm diameter embedded in the Y2O3 matrix. The thin MgO rods and the associated residual stress field contribute to the material strength as they deviate the propagating crack. The Vickers Hardness ranged from 9.5 to 11.5 GPa, with mild increase with the decrease of the microstructural size which has been rationalized as the MgO rods blocking the movement of dislocations in the matrix, as in other studied composites. Indentation fracture toughness values around 3 MPa.m1/2, independent of the sample microstructure, have been measured. In the longitudinal direction transmittance values higher than 80 % in the wavelength range from 3.5 to 7 μm, for 1 mm thick slices have been measured. Light scattering limits the short wavelength cut-off to around 2 μm for light travelling in the longitudinal direction, while a transmittance gap is observed in the transverse direction, of photonic crystal like nature.

A Platform for Complementary Metal‐Oxide‐Semiconductor Compatible Plasmonics: High Plasmonic Quality Titanium Nitride Thin Films on Si (001) with a MgO Interlayer

Titanium nitride (TiN) is highly attractive for plasmonics and nanophotonics applications owing to its gold‐like but tunable optical properties. Its prodigious potential for plasmonics has been demonstrated on sapphire or bulk MgO. For a transformational impact, high optical quality TiN on Si is required instead, which would support the integration of nanophotonics with the complementary metal‐oxide‐semiconductor (CMOS) electronics. However, TiN grown on Si, even at elevated temperatures, lacks the optical quality needed, imposed by the large lattice mismatch between them. Here, a novel approach is reported wherein a thin MgO interlayer is inserted between TiN and Si. The improved crystalline quality enabled by MgO for TiN on Si(001) leads to a significant enhancement of the plasmonic figure of merit (FOM = −ε′/ε″) from 2.0 to 2.5 at telecommunication wavelength (peak FOM of 2.8), which is comparable to the widely accepted ultimate FOM obtained on bulk MgO grown under similar conditions. The TiN/MgO/Si structure enables the hybrid‐plasmonic‐photonic waveguide platform with sufficiently low losses, and thus long propagation lengths, for nanophotonic devices while providing additional practical advantages such as serving as a self‐aligned robust etching mask. Thus, the much‐anticipated potential of TiN on Si platform for CMOS compatible plasmonics is brought closer to reality.

MgGa2O4 as alternative barrier for perpendicular MRAM junctions and VCMA

The CoFeB/MgO/CoFeB magnetic tunnel junction (MTJ) is the central element of any high performance perpendicular Magnetoresistive Random Access Memory (MRAM) device. The MgO tunnel barrier, in contact with CoFeB films at both sides in the magnetic tunnel junction, provides a high tunnel magneto resistance (TMR) and perpendicular magnetic anisotropy (PMA) thanks to the high crystalline quality of the MgO/CoFeB interface achieved upon post-deposition annealing. We study MgGa2O4 as an alternative barrier material due to its lower bandgap and show how to introduce it into state-of-the-art perpendicular MRAM stacks. We demonstrate that thin MgO films at both sides of the barrier are key to ensure a proper crystallization and induce reference layer and free layer perpendicular magnetic anisotropy. Consequently, a stack incorporating a MgGaxOy barrier with full PMA and TMR > 100% can be fabricated with a resistance-area (RA) product as low as 50 Ω μm2, which is of strong interest as a potential barrier in the field of voltage control magnetic anisotropy MRAM.

Texture of YBCO layer grown on GaN/c-sapphire substrates

YBCO thin films with epitaxial alignment were grown on (0001) oriented GaN/c-sapphire substrates using pulsed laser deposition. We performed a complete texture analysis and proposed a qualitative texture model explaining the measured X-ray pole figures of the YBCO films. The analysis revealed three texture components with the planes {001}, {113} and {207} parallel to the (0001) plane of the GaN surface. The six-fold symmetry of the GaN surface caused that all three texture components comprise six orientation variants. The orientation relationship of the variants with respect to the GaN/c-sapphire substrate was established. It was shown that thin MgO interlayer deposited on GaN/c-sapphire substrate before the growth of the YBCO layer can suppress the formation of the undesirable {113} and {207} texture components.

Invisible Surface Oxygen Vacancies in a Thin MgO Film: Impacts on the Chemical Activity and Secondary Electron Emission.

Today, Fs defects in MgO as isolated surface neutral oxygen vacancies are in the focus of surface science, catalysis research, and emission coating of microchannel plates. With the 10-4 atom % content at 750 K and under pO2 = 10-9 Torr, estimated by us from the known equilibrium T-x and p-T-x diagrams of MgO, Fs defects remain invisible or difficult-to-detect objects. The MgO(100) → MgO(100) + Fs + 1/2O2 phase transition was studied in MgO films deposited by the metal-organic chemical vapor deposition (MOCVD) procedure from the mixed-ligand Mg precursor on Si substrates at 725 K in the O2 flow where the nonstoichiometric phase (MgO/Fs) is formed in the gas medium containing simultaneous H2, CO, H2O, CO, and O2 species in unbalanced concentrations. Realization of the above transition was proven theoretically and experimentally through kinetic-thermodynamic analysis of the nonequilibrium system with revealing thermodynamic motive forces, i.e., the positive enthalpy and entropy, as well as through a new combination of diagnostic methods including the original differential dissolution method, due to which separate determination of the point and morphological defects was achieved. It was found that Fs defects occur when oxygen in the immediate vicinity to the substrate surface is replaced practically completely by the oxidized products of the precursor and the resulting oxygen pressure becomes enough for this process. The 90 mass % of the as-deposited MgO-film-involved (MgO/Fs) phase; its chemical activity is demonstrated through dissolution in hot water, while the electron donor activity is through 9 at 750 eV secondary electron yield. A good understanding of gas-phase reactions between the precursors and oxygen provides the fundamental basis of the MOCVD process to deposit MgO films that are dense, free from carbon, and of homogeneous texture. This makes the MOCVD process suitable also for use as coatings of microchannel plates.

Asymmetric Hysteresis Loops in Co Thin Films

Asymmetric magnetic hysteresis loops are usually found in exchange bias (EB) systems, typically after field cooling a system below the Néel temperature of an antiferromagnet exchange coupled to a ferromagnet. Alternatively, asymmetric hysteresis loops may occur due to undetected minor loops or in systems with a rotational anisotropy. Here, we report on an exchange bias thin film system MgO(100)/Co/CoO, examined at room temperature, which is far above the blocking temperature, by the magneto-optical Kerr effect (MOKE). While the longitudinal hysteresis loops partly show steps which are well-known from diverse purely ferromagnetic systems, the transverse hysteresis loops exhibit clear asymmetries, similar to exchange biased systems at low temperatures, and unusual transverse magnetization values at saturation. Since minor loops and a rotational anisotropy can be excluded in this case, this asymmetry can possibly be a residue of the exchange bias coupling at lower temperatures.

Synergetic Effect of Plasmonic Gold Nanorods and MgO for Perovskite Solar Cells.

We report new structured perovskite solar cells (PSCs) using solution-processed TiO2/Au nanorods/MgO composite electron transport layers (ETLs). The proposed method is facile, convenient, and effective. Briefly, Au nanorods (NRs) were prepared and introduced into mesoporous TiO2 ETLs. Then, thin MgO overlayers were grown on the Au NRs modified ETLs by wet spinning and pyrolysis of the magnesium salt. By simultaneous use of Au NRs and MgO, the power conversion efficiency of the PSC device increases from 14.7% to 17.4%, displaying over 18.3% enhancement, compared with the reference device without modification. Due to longitudinal plasmon resonances (LPRs) of gold nanorods, the embedded Au NRs exhibit the ability to significantly enhance the near-field and far-field (plasmonic scattering), increase the optical path length of incident photons in the device, and as a consequence, notably improve external quantum efficiency (EQE) at wavelengths above 600 nm and power conversion efficiency (PCE) of PSC solar cells. Meanwhile, the thin MgO overlayer also contributes to enhanced performance by reducing charge recombination in the solar cell. Theoretical calculations were carried out to elucidate the PV performance enhancement mechanisms.

Dynamics of Photo-Generated Carriers across the Interface between CsPbBr3 Nanocrystals and Au-Ag Nanostructured Film, and Its Control via Ultrathin MgO Interface Layer.

The dynamics and control of charge transfer between optoelectronically interesting and size-tunable halide perovskite quantum dots and other juxtaposed functional electronic materials are important issues for the emergent device interest involving such a family of materials in heterostructure configurations. Herein, we have grown bimetallic Au–Ag thin films on glass by pulsed laser deposition at room temperature, which bear nanoparticulate character, and the corresponding optical absorption spectra reveal the expected surface plasmon resonance signature(s). Subsequently, spin-coated CsPbBr3 nanoparticle films onto the bimetallic Au–Ag films exhibit surface-enhanced Raman scattering as well as strong photoluminescence quenching, the latter reflecting highly efficient transfer of photo-generated carriers across the CsPbBr3/Au–Ag interface. Surprisingly, when an ultrathin MgO (insulating) layer of optimum thickness is introduced between the CsPbBr3 and Au–Ag films, the charge transfer is further facilitated with the average lifetime of carriers becoming even shorter. By changing the thickness of the thin MgO layer, the carrier lifetime can in fact be tuned; with the charge transfer getting fully blocked for thick enough MgO layers, as expected. Our study thus throws light on the charge-carrier dynamics in halide perovskites, which is of importance to emergent optoelectronic applications.

AlN and MgO thin-layer coatings on the bendable polymeric substrates as selective filters for IR and THz spectral ranges

Thin AlN and MgO poly- or nano-structured layers were synthesized on bendable polymeric substrates using the helicon-arc ion-plasma method. They can be used as filters to block infrared (IR) radiation from civil and military objects. To suppress IR radiation within the range λ ~ 7.5…25 µm, where most of the radiation power from objects with the temperature T ~ 300…400 K is concentrated, we have used AlN and MgO thin layers (d ~ 1.5…10 μm) that have the Restrahlen bands within the spectral range indicated above. The optical, structural properties and chemical composition of AlN and MgO films on the Mylar or Teflon substrates have been investigated. These filters demonstrate blocking characteristics for masking the thermal image of objects heated to a temperature of 300…400 K in the IR spectral range. At the same time, they are well transparent in the microwave and THz spectral ranges (transparency τ up to ≈ 80…85%). Moreover, thin Mylar films with AlN coatings are transparent in the visible range. Using the combined coatings of AlN with high thermal conductivity (110…140 W/m·K in the polycrystalline form) for heat withdraw to the periphery or air and MgO coatings, one can suppress IR radiation by more than 90% within the spectral range λ = 7.5…25 μm.

Ultraviolet Photoconductive Detector Based on MgO/a-GaN Heterostructure Grown by Aqueous Method.

Thin MgO nanostructure layer was grown on a-plane GaN film in this study using low temperature aqueous method. The thin MgO layer showed uniform sheet-like morphology. Meanwhile, ultraviolet (UV) photoconductive detector based on MgO/a-GaN heterostructure was fabricated by simple way. The obtained detector displayed excellent UV sensing properties. Results showed that the thin MgO nanostructure layer can effectively decrease the dark current and passivate the surface defects. The facile method will provide a new route to adopt nanostructures for applications in enhancing the performance of GaN-based UV detector.

Strained lateral structure and its relaxation in a Cu2O thin crystal epitaxially grown on MgO surface

We measured in-plane X-ray diffraction and investigated the strained lateral structure and its relaxation in a Cu2O thin crystal epitaxially grown in a small gap between paired MgO substrates. Although one side MgO was peeled off to irradiate Cu2O with X-ray, a thin MgO layer remained on Cu2O, and diffraction peaks of (400)-planes in both MgO and Cu2O were detected. The peak has four-fold symmetry on sample rotation, and the lattice constant estimated from the diffraction angle is 4.254 Å. The lattice constant is larger than that of MgO and smaller than that of strain-free Cu2O. Furthermore, it was found that the lattice strain in Cu2O relaxes at a depth of ≈0.15 μm from MgO on the basis of the estimated X-ray penetration depth under consideration of low incident angle, absorption and refraction of X-ray.

Theoretical and experimental investigation of secondary electron emission characteristics of MgO coating produced by atomic layer deposition

Atomic layer deposition (ALD) is utilized to prepare thin MgO coatings 1–50 nm on Si substrate. In addition, secondary electron emission (SEE) coefficient of MgO/Si double-layered structure is evaluated as a function of coating thickness and primary electron (PE) energy. After neutralizing the surface of test specimen, we have accurately analyzed the relationship between secondary electron yield (SEY) of MgO coating and PE energy. Meanwhile, SEE characteristics of MgO/Si double-layered structure have been systematically analyzed. A maximum SEY value of 6.15 has been achieved at coating thickness of 30 nm and PE energy of 550 eV. Furthermore, theoretical model is established by using Dionne's SEE model to analyze experimentally measured SEY data, demonstrating consistency between experimentally measured and theoretically calculated results. This work demonstrates that SEE level of MgO coating can be optimized by tuning coating thickness and presents novel insights into SEE characteristics of composite materials. Those results can serve as a baseline for further design and fabrication of a wide array of electronic devices.

Adsorption and Thermal Decomposition of Electrolytes on Nanometer Magnesium Oxide: An in Situ 13C MAS NMR Study

Mg batteries have been proposed as potential alternatives to lithium-ion batteries because of their lower cost, higher safety, and enhanced charge density. However, the Mg metal readily oxidizes when exposed to an oxidizer to form a thin MgO passivation surface layer that blocks the transport of Mg2+ across the solid electrode-electrolyte interface (SEI). In this work, the adsorption and thermal decomposition of diglyme (G2) and electrolytes containing Mg(TFSI)2 in G2 on 10 nm-sized MgO particles are evaluated by a combination of in situ 13C single-pulse, surface-sensitive 1H-13C cross-polarization (CP) magic-angle spinning (MAS) nuclear magnetic resonance, and quantum chemistry calculations. At 180 °C, neat G2 decomposes on MgO to form surface-adsorbed -OCH3 groups that are captured as a distinctive peak located at about 50 ppm in the CP/MAS spectrum. At low Mg(TFSI)2 salt concentration, the main solvation structure in this electrolyte is solvent-separated ion pairs without extensive Mg-TFSI contact ion pairs. G2, likely including a small amount of G2-solvated Mg2+, adsorbs onto the MgO surface. At high Mg(TFSI)2 salt concentrations, contact ion pairs between Mg and TFSI are formed extensively in the solution with the first solvation shell containing one pair of Mg-TFSI and two G2 molecules and the second solvation shell containing up to six G2 molecules, namely, MgTFSI(G2)2(G2)6+. In the presence of MgO, MgTFSI(G2)2(G2)6+ adsorbs onto the MgO surface. At 180 °C, the MgO surface stimulates a desolvation process converting MgTFSI(G2)2(G2)6+ to MgTFSI(G2)2+ and releasing G2 molecules from the second solvation shell of the MgTFSI(G2)2(G2)6+ cluster into the solution. MgTFSI(G2)2+ and MgTFSI(G2)2(G2)6+ tightly adsorb onto the MgO surface and are observed by 1H-13C CP/MAS experiments. The results contained herein show that electrolyte composition has a directing role in the species present on the electrode surface, which has implications on the structures and constituents of the solid-electrolyte interface on working electrodes and can be used to better understand its formation and the failure modes of batteries.