Change In Lattice Constant Research Articles

Indirect characterization of point defects in proton irradiated ceria

A rate theory model informed by multimodal characterization is used to evaluate the concentration of point defects in irradiated materials. Cerium dioxide (CeO2) is used as a model ionic compound, whose cation and anion sublattice point defects evolve independent of each other, but extended defects in the form of dislocation loops retain stoichiometry of the compound. To demonstrate this, we performed extensive measurement of defect evolution in CeO2 exposed to energetic protons at elevated temperature. Two sintered polycrystalline CeO2 samples were irradiated with protons having energies up to 2.5 MeV. Both samples were irradiated at 600°C to a dose of 0.14 dpa, but with different dose rates. These irradiation conditions produced a rich microstructure with resolvable extended defects and a significant concentration of point defects. Dislocation loop density revealed by electron microscopy and lattice constant changes measured by X-ray diffraction (XRD), and mesoscale thermal conductivity measurements were used to parameterize the rate theory model. The model, which includes point defect generation, recombination, and clustering into stoichiometric interstitial loops, suggests a large concentration of cerium vacancies and interstitials is present under these irradiation conditions. This work lays the foundation for expanded multimodal characterization of microstructure, including more direct characterization of point defects using optical spectroscopies.

Structural, morphological, optical and enhanced photodetection activities of CdO films: An effect of Mn doping

In this work, undoped and Mn of various concentration (1, 3 and 5 %) doped CdO films prepared by spray pyrolysis procedure using perfume atomizer is reported. XRD analysis of the samples approves polycrystalline nature with cubic system. Change in crystallite size, lattice constant, and cell volume are observed due to the imperfection of crystal lattice. Tightly packed uniformed spherical shape particles are visualised from the morphology anaysis. In PL studies, the emission peaks are observed at 360, 490, 520, and 590 nm. From the UV–vis, the absorbance is increased with doping concentration, which may be due to electronic transition from V to C-band. The bandgap values are decreased with increasing doping concentration (2.51, 2.47 and 2.21 eV) and furher increased for higher doping concentration (2.37 eV). The high resistivity obtained for 3% Mn doped film may be the vital to decrease the dark current and increase the photodetector properties. I–V characteristics of the devices showed increased photosensitivity, responsivity, and quantum efficiency for 3 % of Mn doped film due to high crystallinity, low bandgap, and maximum energy transfer of Mn ions.

Study of microstructure, electronic structure and thermal properties of Al2O3-doped tetragonal YSZ coatings

Al2O3-doped tetragonal yttria-stabilized zirconia (t-YSZ) coatings were prepared by plasma spraying under various spraying parameters. The analysis of variance reveals that only Al2O3 addition significantly affects thermal properties of coatings. The electronic structures and microstructures results show that the increase in number of defects and boundary density with the increasing addition of Al2O3 enhances phonon scattering resulting in a decrease in the thermal conductivity, which suggests that the Al2O3 addition can improve the insulation performance of the YSZ coating. The increase in boundary density with the increase in Al2O3 addition is due to recrystallization resulting from the decreasing melting point of Al2O3–YSZ composites, lattice distortion, and the presence of amorphous structure and monoclinic Al2O3 pinning at grain boundaries. The change in the coefficient of thermal expansion with Al2O3 addition is attributable to the variation in the bonding strength of the Al2O3-doped t-YSZ caused by the change in lattice constants.

Synthesis of Ni-Cr-B-Si-Fe-based interlayer alloy for transient liquid phase bonding of Inconel 718 superalloy by mechanical alloying process

A Ni-Cr-B-Si-Fe-based filler alloy powder has been synthesized by mechanical alloying technique in a high-energy ball mill to join Inconel 718 (IN 718) by transient liquid phase (TLP) bonding. The structural analysis of the synthesized alloy powders was done by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), field emission transmission electron microscope (FETEM), and laser particle size analyzer (LPSA). Thermal characterization was done by differential scanning calorimetry (DSC). The particle size of 60-h milled powders was found to be 15.4 μm and exhibits equiaxed shapes. Analysis of results reveals that during the milling process, elemental powder mixture gradually transforms to a nano-crystalline non-equilibrium face-centered cubic structured (FCC) Ni (Cr, Fe, Si, B) solid solution alloy. For the powder after 60-h milling, the crystallite size measured by XRD was found to be 4.0 nm. The lattice constant of nickel in the milled powder mixture decreased up to 5 h of milling and increased with a further increase in milling time. Dissolution of Si, B, Cr, and Fe into the Ni matrix resulted in the change of lattice constant of the alloy powder. The DSC result of 60-h milled powders reveals an endothermic peak at 1023.5 °C, which is attributed to the melting of the alloy powder. The activation energy of the milled powder reduced with milling time; as a result, the diffusivity of the elements in the filler metal increased. The activation energy of the 60-h milled alloyed powders was found to be 2714.67 KJ/mol. IN 718 superalloy was joined by the TLP bonding process. The microstructure of the TLP-bonded IN 718 joints showed three distinct zones in the bond area. Increasing the bonding temperature from 1050 to 1100 °C resulted in a 21% increase in the shear strength of TLP-bonded IN 718 alloy.

Enhancement of Bc2 and Birr in bulk MgB2 superconductors with SnO2 Additions

Three (MgB2)1-x(SnO2)x samples with x ranging from 0 to 5 wt% were prepared by the in situ route to study the effect of tin dioxide additions on the superconducting properties of MgB2 bulk materials. All of the reacted samples were slightly Mg deficient although the starting Mg:B precursor powder ratio was 1:2. A heat treatment (HT) temperature of 700 °C with a dwell time of 30 min was used. XRD results showed evidence of peak shifts for MgB2 phases with SnO2 addition. The magnitude of the a-axis lattice constant change (0.361 ± 0.075 %) calculated for the 3 wt% doped samples is comparable in magnitude to that seen previously for the C-doped MgB2 bulks which exhibited enhanced BC2. The upper critical fields (BC2) and the irreversibility fields (Birr) were measured resistively in fields up to 14 T at 5 K to Tc. The best BC2 value at 20 K (15.2 T based on extrapolation) was seen for sample IS3 (x =3 wt%), and was comparable to the best BC2 values (≈ 15 T at 20 K) seen for C-doped MgB2 bulks. IS3 had a corresponding Birr = 10.8 T (20 K). The superconducting transition temperature (Tc) appeared to increase slightly with doping, although within the range of error bars (37.4 K to 37.6 K for 1.6 T BC2 increase at 20 K), in contrast to C doping which is accompanied by a significant decrease in Tc (39 K to 36 K for 3.8 % C doped MgB2 bulk). We attribute the observed increase in both BC2 and Birr for SnO2-additions to lattice strain caused by the introduction of precipitates within the grains.

Microstructure and Microwave Absorption Characteristics of BaTiO<sub>3</sub>-CoFe<sub>2</sub>O<sub>4</sub> Composites

Magnetic and dielectric phases like CoFe2O4 and BaTiO3 are both intrinsically capable of absorbing electromagnetic waves. The characteristics of the two phases in a composite structure to obtain the combined effect of the existence of phases as composite components have been investigated. Observation of the microstructure of composites with the composition (1-x)BaTiO3-(x)CoFe2O4 has shown the compact structure of composite sample with an increased the mass density with increasing value of x. No changes in lattice constant of each phase in the composite structure. This ensures that no complete or partial substitution between the ions of each phase has occurred. However, the presence of a material phase in the composite structure influenced the crystallite growth behavior of each phase. The mean crystallite size of the two phases tends to increase, but grew with a different rate. The saturation magnetization value of the composite samples is composition dependent. The value of remanent magnetization and coercivity increases with increasing values of x. All composite samples based on the results of data evaluation data taken by a vector network analyzer (VNA) in X-band frequency, shows the ability to absorb electromagnetic waves in all X-band frequencies. Composite composition determined the peak frequency that gives the maximum reflection loss value. The largest maximum reflection loss value is-40 dB occurring at a frequency of 10.98 GHz from samples with a composition x = 0.5. In conclusion, the composite of CoFe2O4/BaTiO3 system composite can be a promising candidate for electromagnetic wave dampers when the composite is properly designed.

Cation-Deficiency-Induced Crystal-Site Engineering for ZnGa2O4:Mn2+ Thin Film.

Zn-deficient spinel-type ZnGa2O4:Mn2+ phosphor thin films were prepared using pulsed laser deposition. With an increase (decrease) in the Zn deficiency (concentration) of the films, changes in lattice constant, optical band gap, and photoluminescence spectra were observed. All films without γ-Ga2O3:Mn showed green luminescence attributable to the transition from the 4T1 state to the 6A1 state. In addition, the spectral shape changed depending on the temperature. The luminescence spectra have two peaks resulting from the Mn2+ ions located in the tetrahedral and octahedral sites. These peaks had different thermal quenching temperatures, which were around 320 and 260 K, respectively. Therefore, the spectral shape changed with increasing temperature. The spectral shape also depended on the Zn concentration. With an increase (decrease) in the Zn concentration (deficiency) of the films, the intensity of emission from Td increased in comparison with that from Oh. Therefore, the position of Mn2+ was controlled by Zn deficiency similarly to the effect of crystal-site engineering.

Pressure induced structural behavior of energetic cocrystal TNT/TNB: a density functional theory study

In order to find out the relationship between external pressures and properties of energetic materials, we used the density functional theory (DFT) method to investigate the structural, electronic, and absorption properties of crystalline 2,4,6-trinitrotoluene (TNT)/2,4,6-trinitrotoluene (TNB) under hydrostatic compression of 0-100GPa. By analyzing the change of lattice constants (a, b, and c) of TNT/TNB under compression conditions, we found that variation tendency of the lattice constants was anisotropic. The b-axis is much stiffer than that along the a- and c-axes, which indicates that the TNT/TNB crystal is anisotropic within a certain pressure region. The pressure-induced structure transformation results in the new covalent bonds O11-C13, O12-C11, O8-C4, and O1-C12 at 60GPa, and O4-C5 at 80GPa, respectively. By analyzing the band structure and density of states of TNT/TNB in the pressure range over 40GPa, the electronic structure of TNT/TNB changed to metallic system, which indicated it becomes more sensitivity under high pressures. The pressure-induced structure transformation of TNT/TNB also contributed to the relatively high optical activity of TNT/TNB at 70GPa.

In-situ stretching strain-driven high piezoelectricity and enhanced electromechanical energy-harvesting performance of a ZnO nanorod-array structure

Abstract Although strain engineering has been extensively recognized as a critical pathway in controlling the properties of inorganic materials, there have been very limited reports on the external strain-dependent modulation of piezoelectricity in flexible systems. Herein, we introduce a technical way of imposing extra stress during the deposition of the ZnO nanorods by using the stretching mode of a polymer substrate, specifically for the purpose of enhancing piezoelectricity and bending-driven energy harvesting performance. Depending on the level of stretching up to 4.87% strain, the induced stress of the nanorod structure was modulated after the substrate-releasing step. The 4.87%-stretching mode resulted in an effective piezoelectric coefficient of 33.3 p.m./V corresponding to an enhancement by ~270% compared to the unstrained case. The resultant piezoelectric energy harvester demonstrated ~3.43 V output voltage and ~226 nA output current for the 4.87%-strained sample, which means respective increments by ~90% and ~85% with the application of in-situ strain. The origin of the improvements is chased by estimating the changes in lattice constants and spontaneous polarization, which are dependent on the level of in-situ strain.

Dynamic simulation of growth of NaYF4 nanocrystals at high temperature and pressure

Abstract The s-NaYF4 with low phonon energy and good chemical stability was reported as one of the best up-conversion hosts. However, due to the difficulty in in-situ monitoring the crystal growth process at high temperature and pressure, the effects of pressure and temperature on s-NaYF4 crystal growth are not better explained. This paper simulates the in-situ growth process of s-NaYF4 crystal at high temperature and pressure by using the molecular dynamics theory, and calculates the surface free energy of different crystal planes to judge the growth trend of s-NaYF4 crystal. The results show that the optimal temperature and pressure conditions for s-NaYF4 crystal growth are 460 K and 620 kPa, and the surface free energy of the (0001) crystal plane is the largest and this plane is easiest to grow. The final crystal will grow into a hexagonal prism, which is consistent with the experiment results. The lattice constant change of the (0001) crystal plane of the s-NaYF4 crystal was calculated, and the density of the crystal gradually became higher as the temperature and pressure increased linearly. This work proposes a good method to simulate crystal growth at high temperature and pressure.

Bi-directional tuning of thermal transport in SrCoOx with electrochemically induced phase transitions.

Unlike the wide-ranging dynamic control of electrical conductivity, there does not exist an analogous ability to tune thermal conductivity by means of electric potential. The traditional picture assumes that atoms inserted into a material's lattice act purely as a source of scattering for thermal carriers, which can only reduce thermal conductivity. In contrast, here we show that the electrochemical control of oxygen and proton concentration in an oxide provides a new ability to bi-directionally control thermal conductivity. On electrochemically oxygenating the brownmillerite SrCoO2.5 to the perovskite SrCoO3-δ, the thermal conductivity increases by a factor of 2.5, whereas protonating it to form hydrogenated SrCoO2.5 effectively reduces the thermal conductivity by a factor of four. This bi-directional tuning of thermal conductivity across a nearly 10 ± 4-fold range at room temperature is achieved by using ionic liquid gating to trigger the 'tri-state' phase transitions in a single device. We elucidated the effects of these anionic and cationic species, and the resultant changes in lattice constants and lattice symmetry on thermal conductivity by combining chemical and structural information from X-ray absorption spectroscopy with thermoreflectance thermal conductivity measurements and ab initio calculations. This ability to control multiple ion types, multiple phase transitions and electronic conductivity that spans metallic through to insulating behaviour in oxides by electrical means provides a new framework for tuning thermal transport over a wide range.

Field and temperature dependence of the skyrmion lattice phase in chiral magnet membranes

Magnetic skyrmions are nanosized magnetization whirls that exhibit topological robustness and nontrivial magnetoelectrical properties, such as emergent electromagnetism and intriguing spin dynamics in the microwave-frequency region. In chiral magnets, skyrmions are usually found at a pocket in the phase diagram in the vicinity of the ordering temperature, wherein they order in the form of a hexagonal skyrmion lattice (SkL). It is generally believed that this equilibrium SkL phase is a uniform, long-range-ordered magnetic structure with a well-defined lattice constant. Here, using high-resolution small-angle resonant elastic x-ray scattering, we study the field and temperature dependence of the skyrmion lattice in FeGe and Cu2OSeO3 membranes. Indeed, Cu2OSeO3 shows the expected rigid skyrmion lattice, known from bulk samples, that is unaffected by tuning field and temperature within the phase pocket. In stark contrast, the lattice constant and skyrmion size in FeGe membranes undergo a continuous evolution within the skyrmion phase pocket, whereby the lattice constant changes by up to 15% and the magnetic scattering intensity varies significantly. Using micromagnetic modeling, it is found that for FeGe the competing energy terms contributing to the formation of the skyrmion lattice fully explain this breathing behavior. In contrast, for Cu2OSeO3 this stabilizing energy balance is less affected by the smaller field variation across the skyrmion pocket, leading to the observed rigid lattice structure.

Relationship Between Basal Plane Dislocation Distribution and Local Basal Plane Bending in PVT-Grown 4H-SiC Crystals

The inhomogeneous distributions of basal plane dislocations (BPDs) in PVT-grown 4H-SiC crystal boule due to internal stresses cause lattice plane bending, which strongly affect SiC-based device fabrication. The relationship between BPDs and local basal plane bending in 6-inch 4H-SiC substrates has been investigated. Synchrotron monochromatic beam x-ray topography (SMBXT) imaging shows black and white contrast of BPDs with Burgers vectors of opposite signs based on the principle of ray tracing. We have evaluated the net difference of BPDs with black and white contrast along both [11$$ \bar{2}$$0] and [1$$ \bar{1}$$00] radial directions on the Si face across multiple 6-inch diameter 4H-SiC substrates sliced from the same and different boules and predicted the nature (concave/convex) and amount of bending of the basal plane in these wafers. Line scans of 0008 reflection using high resolution x-ray diffractometry (HRXRD) has been carried out along the two directions to verify the nature of bending in these wafers. Results show quite different bending behavior along [11$$ \bar{2} $$0] and [1$$ \bar{1}$$00] directions, indicating that the Si face of 6-inch substrates creates non-isotropic bending on the basal plane. These observations are correlated quite well with net BPD density analysis. The physical shapes of the wafers were also measured to be not flat due to the surface effect. Quantitative analysis of the degree of basal plane bending based on the SMBXT data was carried out and found to be correlating well with the measured tilt angle from HRXRD. Existence of a high stress center was observed in one of the 6-inch wafers resulting in severe bending which is associated with both large bending angles and abrupt changes in lattice constants a and c.

<i>In situ</i> Neutron Diffraction on Ferrite and Pearlite Transformations for a 1.5Mn-1.5Si-0.2C Steel

The phase transformation behavior from austenite upon cooling in a 1.5Mn-1.5Si-0.2C steel was in situ monitored using dilatometry, X-ray and neutron diffractions. The starting temperature of ferrite transformation was in good agreement between dilatometry and neutron diffraction, whereas much higher in X-ray diffraction. Such a discrepancy in transformation temperature is attributed to the change in chemical composition near the surface of a specimen heated to elevated temperatures in a helium gas atmosphere for X-ray diffraction. In situ neutron diffraction enables us to investigate the changes in lattice constants of ferrite and austenite, which are affected by not only thermal contraction but also transformation strains, thermal misfit strains and carbon enrichment in austenite. Pearlite transformation started after carbon enrichment in austenite reached approximately 0.7 mass% and contributed to diffraction line broadening.

Crystal Structure and Magnetic Properties of Non-Stoichiometric Co<sub>2</sub>MnGa Heusler Alloy

Crystal structure and magnetic properties of Heusler-alloy Co2MnGa were examined systematically using non-stoichiometric compositions of Co and Mn element from the Czochralski as-grown single crystal samples. The crystalline structure of each sample was characterized by means of X-ray powder diffraction technique. Each sample was treated with and without heat treatment at 923 K for 10 hours. The effects of Co and Mn excess were observed in the lattice constants for both treatments. The L21-type crystal structure was observed only for the heat-treated samples. The changes in lattice constants are attributed to the substitution of atomic sites. The excess of Co tends to decrease the crystal volume, in opposite to the excess of Mn. In order to investigate the Slater-Pauling rule in the non-stoichiometric samples, the saturation magnetic moments were measured from the field-dependent magnetization measurement for the as-grown samples at 2 K. The deviation from the Slater-Pauling rule was found in the lower concentration of valence electron which associated to the lower total fraction of both Co and Mn. This indicates that the magnetic interactions of these materials cannot only be contributed to the number of valence electron.

Atomic configuration, unusual lattice constant change, and tunable ferromagnetism in all-d-metal Heusler alloys Fe2CrV-FeCr2V

Abstract In this study, new all-d-metal Heusler alloys Fe50−xCr25+xV25 (x = 0–25) were investigated on the behaviors of atomic configuration, lattice constant change, and ferromagnetism from the aspects of theoretical calculations and experiments. The theoretical calculations found that both end-member compounds Fe50Cr25V25 (x = 0) and Cr50Fe25V25 (x = 25) prefer to crystallize in Hg2CuTi-type (space group: 216) structure rather than Cu2MnAl-type (space group: 225) one. During the whole substitution process, the structure of Fe50−xCr25+xV25 alloys remains Hg2CuTi-type structure, taking the path from 216 to 216, but with different degrees of BC-site disorder. Both the experimental and theoretical results reveal that the lattice constant increases first, and then abnormally decreases, showing a maximum at Cr40, due to the enhanced covalent d-d hybridizations between the transition metals. The magnetic moment and Curie temperature tuned by Cr substitution vary remarkably between 3.3 and 1.15 μB/f.u. and between 700 and 170 K, respectively, which indicates that the Cr substitution for Fe alters the spin polarizations and exchange interactions in the system. These results provide new insights into the atomic configuration, magnetism and bonding effect in all-d-metal Heusler alloys based on the d-d hybridizations.

Accurate determination of strains at layered materials by selected area electron diffraction mapping

The demand for nanoscale strain mapping is increasing with the spread of nanotechnologies. Traditional macroscale strain measurement methods do not have the required spatial resolution, and well-known transmission electron microscopy methods often encounter difficulties that limit their practical application. We evaluate a stage-scan strain mapping method based on nanosized selected area electron diffraction. Two-dimensional scanning of the sample and simultaneous acquisition of diffraction patterns at fixed beam conditions enable the comparison of interplanar distances measured at different places. Accurate determination of the lattice constant changes becomes possible owing to the two-dimensional Gaussian fitting used to determine the exact position of diffraction spots. The results obtained by stage-scan mapping agree well with the reference X-ray diffraction data, and are not affected by elliptical distortion of the diffraction pattern. The simplicity and stability of the stage-scan strain mapping method make it complementary to other transmission electron microscopy based methods for strain mapping.

Synthesis and thermal, optical and magnetic properties of new Mn2+-doped and Eu3+-co-doped scheelites

A series of Mn2+-doped and Eu3+-co-doped calcium molybdato-tungstates, i.e., Ca1−3x−yMny⌷xEu2x(MoO4)1−3x(WO4)3x (0 < x ≤ 0.2222 when y = 0.0200 and 0 < y ≤ 0.0667 when x = 0.1667, ⌷ represents vacancy) materials were successfully synthesized via high-temperature annealing. XRD results confirmed the formation of single, tetragonal scheelite-type phases (space group I41/a). A change in both lattice constants (a and c), lattice parameter ratio c/a and progressive deformation of MoO4/WO4 tetrahedra with increasing Eu3+ as well as Mn2+ contents were observed. The melting point of doped materials is lower than the melting point of pure matrix, i.e., CaMoO4. New materials exhibit strong absorption in the UV range. They are insulators with the optical direct band gap (Eg) higher than 3.50 eV. The Eg values nonlinearly change with increasing dopants concentrations. EPR measurements allowed to establish the nature of magnetic interactions among Mn2+ ions. Additionally, EPR spectra were sensitive on both parameters: Mn2+ and Eu3+ concentration.

Correlation effect on the electronic properties of pair-checkerboard AFM monolayer FeSe: a first-principles study

We presented a study of the influence of on-site Coulomb correlation U and Hund coupling J on the electronic properties of monolayer FeSe in a pair-checkerboard antiferromagnetic (PAFM) state based on Hubbard-corrected density functional theory (DFT + U). The results demonstrated the Hubbard-U have a strong influence on the electronic bands and lattice structure of monolayer FeSe in PAFM state. The in-plane lattice constant changes under U > 1.85 eV has been identified under full structure optimization. Furthermore, the Hund coupling J has significant influence on the electronic bands and exhibits a remarkable orbital selective behavior at U = 0. Additionally, our results also demonstrated the Hund coupling J has a weaker effect on electronic properties of FeSe when U gets larger. These results are useful for elucidating the possible role of correlation strength on the electronics band and magnetic ground state of monolayer FeSe.

Characterising the Structure and Electrochemical Behaviour of Manganese Hexacyanochromate: Highlighting the Role and Importance of Structural Water at Low Potentials.

In recent years Prussian blue analogue materials have received much attention as battery materials. Two distinct transition metal sites connected through cyanide ligands create an open-framework structure containing interstitial sites capable of containing a range of alkali metal cations.1 Compositional control, as well as defect and water content, allow tunability of many properties. They show excellent electrochemical properties and are some of the most promising candidate cathode materials for sodium- and potassium-ion batteries.2 Operating in both aqueous and organic electrolytes they have shown high rate capability and extremely long cycle lives attributed to negligible change in lattice constant on cycling and fast ionic mobility.3 A majority of current literature focuses on hexacyanoferrate's as cathode materials, operating at around 0.8 V vs. SHE. However, to utilise the excellent properties in a full cell you need an anode with comparable cycle life and kinetics. Through exchanging Fe with Mn, manganese hexacyanomanganate had a redox couple at 0 V vs. SHE. This, in combination with copper hexacyanoferrate produced a full cell with an average discharge voltage of 1 V and long cycle life.4 Efforts to produce lower potential PBA materials have often resulted in loss of the cubic structure and reversible capacity ascribable to a conversion-type mechanism.5 In this work we investigate manganese hexacyanochromate as a low potential PBA material. Through substitution of Cr into the structure we have lowered the reduction potential to -0.86 V vs. SHE, whilst operating in a high voltage aqueous electrolyte. This is the lowest reduction potential reported with the confirmation that the open-framework structure is maintained, and reversible capacity arises from sodium insertion into the material. Two types of water in the structure are characterised through high resolution XRD, TGA and FTIR, and the crucial role water plays in electrochemical activity and structural integrity is highlighted. It was found that when operating in a non-aqueous electrolyte the material is dehydrated and during electrochemical reduction the crystalline structure is lost. This study isolates the important role water plays within the structure and that it is vital to consider when investigating low potential PBA materials for alkali-ion batteries. Hurlbutt, K., Wheeler, S., Capone, I. & Pasta, M. Prussian Blue Analogs as Battery Materials. Joule (2018). doi:10.1016/J.JOULE.2018.07.017Song, J. et al. Removal of interstitial H2O in hexacyanometallates for a superior cathode of a sodium-ion battery. J. Am. Chem. Soc. 137, 2658–2664 (2015).Wessells, C. D., Huggins, R. a & Cui, Y. Copper hexacyanoferrate battery electrodes with long cycle life and high power. Nat. Commun. 2, 550 (2011).Pasta, M. et al. Full open-framework batteries for stationary energy storage. Nat. Commun. 5, 3007 (2014).Deng, L. et al. Investigation of the Prussian Blue Analog Co3[Co(CN)6]2 as an Anode Material for Nonaqueous Potassium-Ion Batteries. Adv. Mater. 1802510 (2018). doi:10.1002/adma.201802510 Figure 1