Bronze Phase Research Articles

Proton Intercalation into an Open‐Tunnel Bronze Phase with Near‐Zero Volume Change

AbstractManaging safety and supply‐chain risks associated with lithium‐ion batteries (LIBs) is an urgent task for sustainable development. Aqueous proton batteries are attractive alternatives to LIBs because using water and protons addresses these two risks. However, most host materials undergo large volume changes upon H+ intercalation, which induces intraparticle cracking to accelerates parasitic reactions. Herein, we report that Mo3Nb2O14 bronze exhibits reversible H+ intercalation (200 mAh g−1) with a Coulombic efficiency of 99.7 % owing to near‐zero volume change and solid‐solution‐type phase transition. Combination of experimental and theoretical analyses clarifies that rotation and shrinkage of open tunnels, which consist of flexible corner‐sharing Mo/NbOn polyhedra, relieve local structural distortions upon H+ intercalation to suppress intraparticle cracking. The prototype full cell of an aqueous proton battery with a Mo3Nb2O14 anode operates stably over 1000 charge/discharge cycles. This study reveals the importance of implementing distortion‐relieving voids in host materials to reduce volume change upon charge/discharge.

Proton Intercalation into an Open-Tunnel Bronze Phase with Near-Zero Volume Change.

Managing safety and supply-chain risks associated with lithium-ion batteries (LIBs) is an urgent task for sustainable development. Aqueous proton batteries are attractive alternatives to LIBs because using water and protons addresses these two risks. However, most host materials undergo large volume changes upon H+ intercalation, which induces intraparticle cracking to accelerates parasitic reactions. Herein, we report that Mo3Nb2O14 bronze exhibits reversible H+ intercalation (200 mAh g-1) with a Coulombic efficiency of 99.7% owing to near-zero volume change and solid-solution-type phase transition. Combination of experimental and theoretical analyses clarifies that rotation and shrinkage of open tunnels, which consist of flexible corner-sharing Mo/NbOn polyhedra, relieve local structural distortions upon H+ intercalation to suppress intraparticle cracking. The prototype full cell of an aqueous proton battery with a Mo3Nb2O14 anode operates stably over 1000 charge/discharge cycles. This study reveals the importance of implementing distortion-relieving voids in host materials to reduce volume change upon charge/discharge.

FeSiBCuNbZr amorphous composites decorated with SiO2 and TiO2(B) (bronze phase TiO2) for efficient electromagnetic wave absorption

The application of Fe-based amorphous microspheres in high-performance electromagnetic wave absorbing materials is significantly limited by a single loss mechanism. Utilizing interfacial engineering and magnetic-dielectric synergistic effect is a viable approach to enhance microwave absorption. In this work, FeSiBCuNbZr amorphous microspheres were synthesized using single copper roller melt-spinning method and ball mill method. The finding reveals that the incorporation of SiO2 and TiO2(B) (bronze phase TiO2) shells notably enhances polarization loss and conductive loss. FeSiBCuNbZr@SiO2@TiO2(B) amorphous composites exhibited a minimum reflection loss value of −64.89 dB at a thickness of 2.17 mm and an effective absorption bandwidth (EAB) of 8.08 GHz covering 9–18 GHz at a thickness of 1.9 mm. The exceptional wave absorption performance is ascribed to the combined effect of magnetic loss in the FeSiBCuNbZr amorphous core and dielectric loss from the double-shell structure, while maintaining favorable impedance matching. This work provides a new core–shell FeSiBCuNbZr amorphous composites for efficient electromagnetic wave absorption.

Scalable Synthesis of Bulk TiO2 Hybrids and Its Li-Storage Properties in “Rocking-Chair” Type Full-Cell Assembly with LiNi0.5Mn1.5O4 Cathode

TiO2 as an anode material in lithium-ion batteries (LIB) has abolished hurdles like irreversibility, cycling stability, rate capability, and energy density, which are vital for electrochemical performance. Conventionally, time-consuming and complex techniques like solvothermal methods are employed to synthesize TiO2. We herein open a new avenue towards a simple, scalable, and eco-friendly synthesis of bulk TiO2 anatase/bronze hybrids from sodium meta-titanate through a facile mechano-chemical and ion-exchange process under different temperature conditions (400, 450, and 500 °C). Structural and morphological features are analyzed through various characterization techniques such as XRD, FE-SEM, HR-TEM, and XPS. The bronze phase’s high reversibility, low redox potential, high current rate performance, and high power capability of the anatase phase make the hybrid attractive for fabricating high power and high energy density Li-ion power packs. The Li insertion/extraction properties are studied in half-cell assembly (Li/TiO2), where all three TiO2 hybrids exhibited promising results with an initial discharge capacity >165 mAh g-1 at a current rate of 0.05 A g-1 along with a capacity retention >90% after 100 cycles. A “rocking-chair” type full-cell configuration with high voltage LiNi0.5Mn1.5O4 cathode is fabricated, in which LNMO/TiO2-400 °C displayed a discharge capacity of ~88 mAh g-1 at a current rate of 0.05 A g-1. Moreover, the full cell exhibited a capacity retention of >70% after 100 cycles with a maximum energy density of 192.75 Wh kg-1. Figure 1

High-temperature relaxation and microwave dielectric response of (1-x)BaNd1.76Bi0.24Ti5O14-xBa0.6Sr0.4La4Ti4O15 compounds with adjustable medium-high dielectric constant

Dielectric ceramics in the microwave band are one of the crucial materials for mobile communication technology, and the studying of their phase evolution and defect behavior can help to understand and reduce dielectric loss. In this work, (1-x)BaNd1.76Bi0.24Ti5O14-xBa0.6Sr0.4La4Ti4O15 (x = 0.2, 0.4, 0.6 and 0.8, (1-x)BNT-xBSLT) ceramics were synthesized by solid-state reaction method. X-ray diffraction (XRD) and Raman spectra analysis reveal that tungsten bronze and hexagonal perovskite phases coexist in the ceramics, and BaNd2Ti3O10 is indexed as the main crystalline phase at x = 0.4, 0.6, leading to a deterioration of the microwave dielectric properties. The defect-related relaxation behavior and its effect on microwave dielectric properties were analyzed by dielectric temperature spectrum and thermally stimulated depolarization current (TSDC). The relationship between the dielectric constant and the electric field distribution was solved using the eigenmode of the high frequency structure simulator. In short, the (1-x)BNT-xBSLT ceramics at x = 0.8 exhibit excellent microwave dielectric properties: εr = 47.2, Q×f = 16,800 GHz, and τf = −4.6 ppm/°C. The microwave dielectric response of BNT-BSLT composite ceramics is closely related to the phase composition and defects, which is informative for the development of low dielectric loss ceramics.

Defects introducing and heterostructures engineering synergistically constructing active sites for achieving stable and fast ion transport in sodium-ion batteries

Bronze phase TiO2 (TiO2(B)) has attracted significant interest as potential anode materials for sodium-ion batteries (SIBs) due to its distinctive open tunnel structure, offering abundant insertion sites for Na+-ions. However, the practical application has been hindered by its poor electrical conductivity and insufficient Na+ diffusion kinetics. Herein, we propose a novel strategy that integrates defect introducing and heterostructures engineering to enhance the performance of TiO2(B) anode. Specifically, we aim to induce oxygen vacancies (OVs) into TiO2(B) through N-doping and in-situ growth on MXenes nanosheets, thereby fabricating N-doped TiO2(B)/MXenes (N-TiO-MX) heterostructures. This strategy leverages the synergistic effects of OVs and N-atoms, along with the formation of heterointerfaces, to effectively reduce the bandgap, increase the number of Na+-ion storage sites, and shorten ion diffusion distances. The robust coupling between TiO2(B) and MXenes ensures the structural integrity of N-TiO-MX heterostructures. Consequently, the N-TiO-MX exhibits a high specific capacity of 211.3 mAh g−1 at 0.1 A g−1 after 400 cycles and superior cycling stability with 163.1 mAh g−1 after 1000 cycles at 1.0 A g−1. The study provides unique insights for designing heterostructure materials to achieve high capacity and excellent fast-charging capability.

Relationship between crystal orientation and energy storage capacity in WO3 photoelectrodes for water splitting

For photoelectrochemical water splitting, tungsten trioxide (WO3) films with a monoclinic structure were synthesized on fluorine-doped tin oxide coated glass substrates with a vacuum evaporation method. To control the WO3 film thickness from 0.42 to 5.6 μm, the crystal orientation was intergraded from the (200) crystal plane to the (002) one. In x-ray diffraction measurements, the intensity ratio of the (002) crystal plane to the (200) one was defined as rp. In the WO3 photoelectrode with higher (002)-preferred orientation, the photocurrent continued to flow even when the incident light against the photoelectrode was completely blocked after the irradiation for 60 s. This suggests that hydrogen continues to be produced owing to the electrons charged by the formation of a hydrogen tungsten bronze (HxWO3) phase. After 72 s, the photocurrent density of the WO3 photoelectrode with rp = 42 became one-tenth of the value before the incident light was blocked. This charge release time was remarkably long compared to those of the WO3 photoelectrodes with (200)-preferred orientation and non-orientation. Therefore, it was considered that the hydrogen ion diffusion through the defects in the WO3 crystals tends to occur in the [002] crystal direction. However, the improvement in the (002)-preferred orientation can facilitate the structural change from the WO3 phase to the HxWO3 one for the entire film.

Synthesis and Characterization of Vanadium Doped Hexagonal Rubidium Tungsten Bronze

Attempts have been made to synthesize vanadium doped rubidium hexagonal tungsten bronzes with the nominal composition RbxVyW1-yO3 (x = 0.30, 0.25, and 0.0 ≤ y ≤ x). The samples were synthesized using the solid state synthesis method in a silica glass tube under vacuum at (10-2 Torr) 700°C. The X-ray diffraction measurements reveal that a pure hexagonal tungsten bronze (HTB) phase can be formed with a 60% replacement of W5+ by V5+. The systematic incorporation of vanadium into the HTB lattice, as well as the reduction of V/W-O bond lengths in the xy plane and the lengthening of these bonds in the crystallographic c direction, are also revealed by Rietveld structure refinement of XRD data. The XRD results are supported by FTIR absorption spectra of the oxidized phases. Furthermore, an absorption signature develops as a function of y and exhibits a considerable increase in intensity with the eventual replacement of W5+ by V5+, showing a large decrease in the metallic like contribution and revealing the compounds' nonmetallic nature. Elemental analysis indicates good agreement with nominal values, demonstrating that vanadium was systematically incorporated into the RbxVyW1-yO3 system. Dhaka Univ. J. Sci. 72(1): 77-84, 2024 (January)

Greatly improved energy storage density of SrO2–BaO2–Nb2O5–SiO2–Al2O3–B2O3 glass ceramics by various amount CeO2 doping

Glass ceramic dielectric materials with high power density and high energy density have important application value in the miniaturization and integration of lightweight pulse power devices. In this work, SrO2–BaO2–Nb2O5–SiO2–Al2O3–B2O3 glass ceramics doped with various contents of CeO2 were prepared via high-temperature melting combined with temperature-controlled crystallization process. Results showed that CeO2 doping increased the content of Ba0.27Sr0.75Nb2O5.78 tungsten bronze phase precipitate from the glass matrix in glass ceramics (from 55.7% to 82.2%), thereby increasing dielectric constant of SrO2–BaO2–Nb2O5–SiO2–Al2O3–B2O3 glass ceramics (from 66.5 to 101.9). Besides that, CeO2-doped ceramics exhibited excellent temperature stability and low loss (below 0.015). The highest breakdown strength (1590 kV/cm) and energy density (12.88 J/cm3) were achieved in the ceramic with a CeO2 doping concentration of 3.0 mol.%, being 3.03 times higher than those in undoped glass ceramic. The increase in energy density of the ceramics was attributed to moderate CeO2 doping concentration that improved the crystallinity (from 83.8% to 89.8%) and reduced the interfacial activation energy of the glass ceramics.

Engineering Phase Separation in Niobate Glass through Ab Initio Molecular Dynamics for Enhanced Energy Storage Performance and Unprecedented Thermal Stability in Niobate-Based Glass Ceramics.

The advancement of lead-free glass ceramics (GCs) possessing appropriate energy storage characteristics is crucial for the renewable energy and electronics industry. In this study, we synthesized lead-free GCs predominantly composed of the tungsten bronze phase, Ba3.3Nb10O28.3. Ab initio molecular dynamics initially reveal nonuniform distribution within the Ba/Nb-O regions in niobite glassy melts, offering valuable insights for the subsequent crystallization process. The proposal of a B-site engineering strategy is suggested, which entails the concurrent reduction of grain size and augmentation of the band gap in tungsten bronze GCs doped with Ta. This approach results in a substantial enhancement of the dielectric breakdown strength (BDS). Phase-field simulations have indicated that the refinement of grain sizes plays a pivotal role in augmenting the local electric field distribution and breakdown path, thereby contributing to the enhancement of BDS. As a consequence of these modifications, a notably high recoverable energy density (Wrec) of 5.23 J/cm3 can be achieved, accompanied by an ultrahigh efficiency (η) of 94%, and superior thermal stability in energy storage. These outcomes are particularly evident in the case of 2 mol % Ta2O5-doped P2O5-K2O-BaO-Bi2O3-TeO2-Nb2O5 (PKBBTN-T) GCs, where the Wrec and η can be determined to be 2.87 ± 3% J/cm3 and 95.46 ± 4%, respectively, over a temperature range spanning from 20 to 150 °C. Additionally, this specimen exhibits an exceptionally high discharge energy density (Wdis) of 4.01 J/cm3. This comprehensive investigation, comprising experimental and theoretical analyses, establishes an effective pathway and paradigm for the development of dielectric materials with ultrahigh energy storage properties.

Identifying major phases in the use of land, energy and changing landscapes by agrarian societies (7,000 cal BP-Present) in Cantabrian Spain, based on cultural changes and anthropogenic signals

IntroductionEnacting transitions toward more sustainable management and use of land, energy, and natural resources poses multiple challenges for human societies. Such transitions have been a constant throughout human history and therefore there is a need to learn from them and apply that knowledge to current land-use policies and management. Significant human impact on landscape and environment in Cantabrian Spain has been documented in alignment with the Neolithization (ca. 7,000 cal BP). While the classic approach of identifying cultural phases based on historical and archaeological data has been extensively studied, much less is understood on how such phases are dependent upon increasing anthropogenic influence on the environment.MethodsCantabrian Spain is well-known for its long mining history. Key processes historically shaping landscapes in the region include the implementation of mining/metallurgy industries and extraction of forest resources. These historical processes were characterized, respectively using heavy metal pollution contents (Hg, Zn, Cd, As, Ni, REE, Pb, and 206 Pb/207 Pb) and total arboreal pollen percentages in peat bogs, providing global trends of human impact on the environment. These trends were then compared to climate (temperature and precipitation) and natural vegetation evolution modeling through time.ResultsResults show seven phases of major human impact on the environment: (1) the Copper phase ca. 4,400–4,100 cal BP, (2) the Middle Bronze phase ca. 3,500–3,150 cal BP, (3) the Iron phase ca. 2,800–2,500 cal BP, (4) the Roman phase ca. 2,200–1,750 cal BP, (5) the Medieval phase ca. 1,250–1,000 cal BP, (6) the Colonial phase ca. 650–400 cal BP, and (7) the Industrial phase ca. 150 cal BP-Present.DiscussionFour phases are tightly related to substantial changes in land use and subsistence strategies: (1) Production, with the appearance of productive economies during the Neolithic, (2) Specialization, with the appearance of specialized activities and trade during the Middle Bronze phase, (3) Urbanization, with the first urban centers during the Roman phase, and (4) Globalization, with worldwide colonialism and capitalism economies during the Colonial phase.

Improved energy storage properties of BNT-based ceramics by compositing with tungsten bronze phase

Improved energy storage properties of BNT-based ceramics by compositing with tungsten bronze phase

K0.5FeF3 as a New Zero-Strain Cathode Material for Lithium-Ion Batteries

The stability of the cathode is of crucial importance for the service life of lithium-ion batteries (LIB). In the cathode, the lattice parameter usually changes during (de-)insertion of lithium, which causes various signs of aging that have a negative effect on the capacity of the cell. This problem can be tackled using a specific type of materials called zero-strain (ZS) materials. These materials do not show any (de-)intercalation-induced structural changes and stresses. Such a zero-strain effect was already demonstrated with fluorine-containing materials [1] and even for the similar material K0.6FeF3 [2] for sodium-ion batteries (SIB). In this case, potassium ions are removed in the first cycle and the vacant lattice sites can be used for the incorporation of sodium ions, while keeping the structural integrity of the host material.Complementary to experiments, theoretical atomistic simulations are powerful to develop design criteria for further ZS-materials. Combining experiments and simulations in this work, the structural behavior of the material K0.5FeF3 was investigated when used as a cathode material in a LIB. The synthesis of K0.5FeF3 was achieved by a Rapid Microwave-Enhanced Solvothermal Process, which allowed to obtain the material in a TTB-type (Tetragonal Tungsten Bronze) phase with a high degree of purity. The material was then processed into electrodes, which were galvanostatically cycled against lithium metal. It was shown that the material is suitable for LIB as a cathode material. X-ray diffraction experiments showed that the lattice parameter changed by less than 1% after the incorporation of Li-Ions, in good agreement with the theoretical calculations conducted in parallel. Lattice Parameter Charged Discharged a[Å] 12.74±0.024 12.73±0.006 c[Å] 3.99±0.008 4.00±0.002 Volume [Å3] 647.57±2.67 647.75±0.76 This work was supported by the German Research Foundation (DFG) BI 1636/7-1 and EL 155/29-1.

Rapid Synthesis of AxWO3 (A = H, Na, K) Tungsten Bronze Materials with Strong Near‐Infrared Absorption and Enhanced Photoelectric Anticorrosion Properties

The intrinsic reduction method is extended for the synthesis of tungsten bronzes (TBs), and monoclinic phase hydrotungsten bronze (HWO), tetragonal phase sodium tungsten bronze (NaWO) and hexagonal phase potassium tungsten bronze (KWO) are obtained. The introduction of cations brought a large number of localized state free electrons, which endowed TBs with strong near‐infrared (NIR) absorption and achieved light energy utilization covering almost the entire solar spectrum in the form of localized surface plasmon resonance (LSPR) and small polariton transfer. The strong NIR absorption enhanced the corrosion protection performance of tungsten bronze coatings, especially the HWO coating, which had an increased impedance value of 859.5% compared to the pure epoxy resin. The excellent corrosion resistance of TBs inhibitors can be derived from the strong NIR absorption enhanced photocathodic protection and local magnetic field, which improved the charge transfer resistance of the coating by nearly two orders of magnitude and greatly inhibited the charge movement in the electrochemical corrosion reaction. This study discovered the contribution of oxygen vacancy‐enhanced NIR absorption to the electrochemical anticorrosion properties, expanding the application area of TBs and making an important contribution to innovative anticorrosion strategies.

Study on Growth of Tungsten Bronze Phase from Niobate Perovskite Ceramics in Controlled Atmosphere for Photoferroelectric Applications

AbstractRecent research has found that by introducing A‐site deficiency into Ba/Ni co‐doped (K,Na)NbO3 ABO3‐type perovskite, a beneficial interface for photoferroelectric applications is formed between the perovskite and tungsten bronze (TB) phases. To date, such an interface is formed only spontaneously, and the growth mechanism of the TB phase in the perovskite phase is unclear. This work investigates controlled interface formation using KNBNNO (K0.50Na0.44Ba0.04Ni0.02Nb0.98O2.98) annealed at different temperatures for different durations, and in various atmospheres. Structural, microstructural, and chemical analyses suggest that vacuum, N2, and O2 atmospheres promote the growth of the TB phase from the sample surface, of which the thickness increases with annealing temperature and duration. In contrast, annealing in air does not promote such growth due to lower evaporation of K and Na. Among all atmospheres, the growth starts the earliest, i.e., at 800 °C, in vacuum compared to that as late as 1000 °C in O2. The association of growth of the TB phase with the degree of alkali volatilization that is dependent on the atmosphere, and that with the resultant variation in diffusion rate, uncovers the formation mechanism of the beneficial interface that may also be applicable to other KNN‐based materials for advanced photoferroelectric applications.

Solid-state atomic hydrogen as a broad-spectrum RONS scavenger for accelerated diabetic wound healing.

Hydrogen therapy shows great promise as a versatile treatment method for diseases associated with the overexpression of reactive oxygen and nitrogen species (RONS). However, developing an advanced hydrogen therapy platform that integrates controllable hydrogen release, efficient RONS elimination, and biodegradability remains a giant technical challenge. In this study, we demonstrate for the first time that the tungsten bronze phase H0.53WO3 (HWO) is an exceptionally ideal hydrogen carrier, with salient features including temperature-dependent highly-reductive atomic hydrogen release and broad-spectrum RONS scavenging capability distinct from that of molecular hydrogen. Moreover, its unique pH-responsive biodegradability ensures post-therapeutic clearance at pathological sites. Treatment with HWO of diabetic wounds in an animal model indicates that the solid-state atomic H promotes vascular formation by activating M2-type macrophage polarization and anti-inflammatory cytokine production, resulting in acceleration of chronic wound healing. Our findings significantly expand the basic categories of hydrogen therapeutic materials and pave the way for investigating more physical forms of hydrogen species as efficient RONS scavengers for clinical disease treatment.

Structure and Electrochemical Properties of Bronze Phase Materials Containing Two Transition Metals

Structure and Electrochemical Properties of Bronze Phase Materials Containing Two Transition Metals

Influence of the Precursor Structure on the Formation of Tungsten Oxide Polymorphs.

Understanding material nucleation processes is crucial for the development of synthesis pathways for tailormade materials. However, we currently have little knowledge of the influence of the precursor solution structure on the formation pathway of materials. We here use in situ total scattering to show how the precursor solution structure influences which crystal structure is formed during the hydrothermal synthesis of tungsten oxides. We investigate the synthesis of tungsten oxide from the two polyoxometalate salts, ammonium metatungstate, and ammonium paratungstate. In both cases, a hexagonal ammonium tungsten bronze (NH4)0.25WO3 is formed as the final product. If the precursor solution contains metatungstate clusters, this phase forms directly in the hydrothermal synthesis. However, if the paratungstate B cluster is present at the time of crystallization, a metastable intermediate phase in the form of a pyrochlore-type tungsten oxide, WO3·0.5H2O, initially forms. The pyrochlore structure then undergoes a phase transformation into the tungsten bronze phase. Our studies thus experimentally show that the precursor cluster structure present at the moment of crystallization directly influences the formed crystalline phase and suggests that the precursor structure just prior to crystallization can be used as a tool for targeting specific crystalline phases of interest.

Development of Bronze Phase Titanium Dioxide Nanorods for Use as Fast-Charging Anode Materials in Lithium-Ion Batteries.

Bronze phase titanium dioxide (TiO2(B)) nanorods were successfully prepared via a hydrothermal method together with an ion exchange process and calcination by using anatase titanium dioxide precursors in the alkali hydrothermal system. TiO2 precursors promoted the elongation of nanorod morphology. The different hydrothermal temperatures and reaction times demonstrated that the synthesis parameters had a significant influence on phase formation and physical morphologies during the fabrication process. The effects of the synthesis conditions on the tailoring of the crystal morphology were discussed. The growth direction of the TiO2(B) nanorods was investigated by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The as-synthesized TiO2(B) nanorods obtained after calcination were used as anode materials and tested the efficiency of Li-ion batteries. This research will study the effects of particle morphologies and crystallinity of TiO2(B) derived from a modified hydrothermal method on the capacity and charging rate of the Li-ion battery. The TiO2(B) nanorods, which were synthesized by using a hydrothermal temperature of 220 °C for 12 h, presented excellent electrochemical performance with the highest Li storage capacity (348.8 mAh/g for 100 cycles at a current density of 100 mA/g) and excellent high-rate cycling capability (a specific capacity of 207.3 mAh/g for 1000 cycles at a rate of 5000 mA/g).

Phase-Pure Epitaxial b-Axis-Oriented Bronze TiO2 Films

We demonstrate the heteroepitaxial growth of phase-pure bronze-phase TiO2 films using pulsed laser deposition on MgAl2O4 single-crystal substrates. While the growth on cubic substrates with smaller lattice parameters favors the stabilization of an out-of-plane-oriented anatase phase, and the use of substrates with larger lattice parameters leads to formation of the rutile phase, MgAl2O4 lies in a narrow intermediate range where the bronze phase is stabilized. X-ray diffraction shows that the b-axis is oriented out-of-plane, while the a–c lattice plane lies within the film plane. The bronze films show twinned domains due to their monoclinic structure that are aligned along all four in-plane directions of the MgAl2O4 lattice. In a subsequent step, TiO2 films are grown on top of MgAl2O4-buffered MgO single crystals in order to demonstrate a route to stabilize the bronze phase on a larger variety of substrates. The growth of bronze-type TiO2 films with the unique, open, one-dimensional framework aligned along the film normally may allow for the investigation of its basic functional properties related to ion diffusion that cannot otherwise be studied easily in other crystal forms.