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The heterogeneous integration of ferroelectric BaTiO3 thin films on silicon (Si) and silicon nitride (SiN)‐based platforms for photonic integrated circuits (PICs) plays a crucial role in the development of future nanophotonic thin film modulators. Since the electro‐optic (EO) properties of ferroelectric thin films strongly depend on their crystal phase and texture, the integration of BaTiO3 thin films on these platforms is far from trivial. So far, a conventional integration route using a SrTiO3 template film in combination with high vacuum deposition methods has been developed, but it has a low throughput, is expensive and requires monocrystalline substrates. To close this gap, a cost‐efficient, high‐throughput and scalable method for integrating highly textured BaTiO3 films is needed. Therefore, an alternative method for the integration of highly textured BaTiO3 films using a La2O2CO3 template film in combination with a chemical solution deposition (CSD) process is presented. In this work, the structural and EO properties of the solution‐processed BaTiO3 film are characterized and its integration into an optical ring resonator is evaluated. The BaTiO3 film exhibits a fiber texture, has a large Pockels coefficient (reff) of 139 pm V−1, and integration into a ring resonator‐based modulator shows a VπL of 1.881 V cm and a bandwidth of > 40 GHz. This enables low‐cost, high‐throughput, and flexible integration of BaTiO3 films on PIC platforms and the potential large‐scale fabrication of nanophotonic BaTiO3 thin‐film modulators. [ABSTRACT FROM AUTHOR]

Harnessing the full power of memristors as artificial synapses demands a simple and scalable crossbar architecture enabling their seamless integration into diverse applications. This Letter presents the 3 × 3 memristor crossbar array configuration featuring a grid of interconnected devices. The composition includes Al as the reactive top electrode connecting the device columns and Gd1−xCaxMnO3 (GCMO, x = 0.8) serving as the bottom electrode connecting the device rows as well as the memristive material eliminating the need for additional layers and fabrication steps. Controlled-sized vias through insulating the Al2O3 layer connect the electrodes forming the active interface. The idea is validated with a test sample of 3 × 3 crossbars with the Au/GCMO/Al structure, Au enabling Ohmic contact to GCMO, with device resistive switching ratios mostly around 102 and yield of over 90%. The devised crossbar structure could provide a highly scalable, yet simple, geometry suitable for synaptic networks. [ABSTRACT FROM AUTHOR]

A set of low-cost monometallic Fe, Ni, and bimetallic Fe–Ni bifunctional H–Y-5.1 catalysts with different metal ratios were synthesized by sequential incipient wetness impregnation. The catalysts were characterized in detail by N2 physisorption, Fourier transform infrared spectroscopy with pyridine, inductively coupled plasma optical emission spectroscopy, X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM–SEM), magic angle spinning nuclear magnetic resonance, X-ray photoelectron spectroscopy (XPS), Mössbauer spectroscopy, magnetic measurements, temperature-programmed reduction (TPR), and X-ray absorption spectroscopy (XAS). The results revealed that introduction of Fe led to a decrease of strong acid sites and an increase of medium Brønsted acid sites, while introduction of Ni increased the number of Lewis acid sites. The particle size of iron was approx. 5 nm, being ca. fourfold higher for nickel. XPS demonstrated higher iron content on the catalyst surface compared to nickel. Both Mössbauer spectroscopy and magnetic measurement confirmed the ferromagnetic behavior of all catalysts. In addition, the results from XRD, TEM, XPS, XAS, and magnetization suggested strong Fe–Ni nanoparticle interactions, which were supported by modeling of TPR profiles. Catalytic results of the co-processing of fossil feedstock with lignin-derived isoeugenol clearly showed that both product distribution and activity of Fe–Ni catalysts strongly depend on the metals' ratio and their interactions. Key properties affected by the Fe–Ni metal ratio, which played a positive role in co-processing, were a smaller medial metal nanoparticle size (<6 nm), a lower metal–acid site ratio, as well as presence in the catalyst of fcc FeNi alloy structure and fcc Ni doped with Fe. [ABSTRACT FROM AUTHOR]

A crucial role in the miniaturization of electronic and photonic components is played by the integration of ferroelectric thin films on silicon (Si) or silicon nitride (SiN) based platforms. Since the properties of ferroelectric thin films strongly depend on their texture quality and crystallographic orientation, the integration of thin films on these platforms is far from trivial. Consequently, this leads to slow, complex and expensive integration processes. To bridge this gap, a high-throughput method for the integration of highly textured ferroelectric thin films on Si or SiN-based platforms is needed. Therefore, we have investigated a method to facilitate the integration of fiber textured ferroelectric thin films by using an ultrathin (∼7 nm) self out-of-plane oriented La2O2CO3 template film. In this paper, we report a local deposition route of the La2O2CO3 thin film by the scalable inkjet printing method, its inherent out-of-plane crystal orientation, and its lattice match with various ferroelectric thin films. The use of the La2O2CO3 template film as an integration tool for (Pb(Zr,Ti)O3, BaTiO3, and BiFeO3) thin films eventually results in strongly fiber-textured ferroelectric stacks, regardless of substrate type. Consequently, the La2O2CO3 thin film has the potential to serve as a high-throughput integration tool for fiber textured ferroelectric thin films on Si or SiN-based platforms. Moreover, this integration tool could pave the way for large-scale miniaturization of photonic or electronic devices such as phase modulators, resonators, capacitors, etc. [ABSTRACT FROM AUTHOR]

Despite great attention toward transition metal tellurates especially M3TeO6 (M = transition metal) in magnetoelectric applications, control on single phasic morphology-oriented growth of these tellurates at the nanoscale is still missing. Herein, a hydrothermal synthesis is performed to synthesize single-phased nanocrystals of two metal tellurates, i.e., Ni3TeO6 (NTO with average particle size ∼37 nm) and Cu3TeO6 (CTO ∼ 140 nm), using NaOH as an additive. This method favors the synthesis of pure NTO and CTO nanoparticles without the incorporation of Na at pH = 7 in MTO crystal structures such as Na2M2TeO6, as it happens in conventional synthesis approaches such as solid-state reaction and/or coprecipitation. Systematic characterization techniques utilizing in-house and synchrotron-based characterization methods for the morphological, structural, electronic, magnetic, and photoconductivity properties of nanomaterials showed the absence of Na in individual particulate single-phase MTO nanocrystals. Prepared MTO nanocrystals also exhibit slightly higher antiferromagnetic interactions (e.g., TN-NTO = 57 K and TN-CTO = 68 K) compared to previously reported MTO single crystals. Interestingly, NTO and CTO show not only a semiconducting nature but also photoconductivity. The proposed design scheme opens the door to any metal tellurates for controllable synthesis toward different applications. Moreover, the photoconductivity results of MTO nanomaterials prepared serve as a preliminary proof of concept for potential application as photodetectors. [ABSTRACT FROM AUTHOR]

A complex deposition process of high-temperature superconducting (HTS) thin films and coated conductors is usually optimized by concentrating on the crystalline quality of the material, thus getting the best possible critical temperature and self-field properties. However, most of the HTS power applications that are based on coated conductors act at high magnetic fields, and thus an alternative approach focusing on the formation of an optimal network of columnar flux pinning centers is more reasonable. Therefore, we systematically show how a lengthening of the deposition distance produces perfectly aligned and distinctly longer self-assembled BaZrO3 (BZO) nanorods within the YBa2Cu3O6+x (YBCO) matrix. This method unambiguously enhances in-field properties such as pinning force, critical current density, and its isotropy along the YBCO c axis. The experimental results, especially formation of the c peak where the relative length of the nanorod is a key issue, are confirmed by the vortex dynamics simulations. Finally, we present a semiquantitative model governing the formation of nanorods that explains the experimentally observed improved nanorod growth as a function of the deposition distance via the associated variation of the fractional partial pressure between atomic species within the laser plume. [ABSTRACT FROM AUTHOR]

This article, published in Advanced Functional Materials, discusses the integration of ferroelectric BaTiO3 thin films on silicon and silicon nitride-based platforms. The researchers demonstrate the highly textured BaTiO3 film and its combination with the electro-optic potential of the film. The large Pockels coefficient of 139 pm V−1 allows for the integration of BaTiO3 films on photonic integrated circuit (PIC) platforms, enabling the potential large-scale fabrication of nanophotonic BaTiO3 thin-film modulators. The authors of the article are Jeroen Beeckman, Klaartje De Buysser, and their colleagues. [Extracted from the article]

Hackmanites, a variety of sodalite with the general formula Na8Al6Si6O24(Cl,S)2, are a family of nature‐based smart materials having the ability for reversible photochromism upon UV or X‐ray exposure. Being nontoxic, cheap, and durable, hackmanite would be an optimal material for the visual detection of the presence of X‐rays in simple portable systems. However, its X‐ray‐induced coloring abilities are so far known only qualitatively. In this work, a combination of experimental and computational methods is used to reveal the mechanism of X‐ray‐induced color changing in these materials. Finally, their use is demonstrated both in color intensity‐based X‐ray dosimetry and photochromic X‐ray imaging. [ABSTRACT FROM AUTHOR]

A nanograined YBCO target, where a great number of grain boundaries, pores etc. exist, is shown to hold an alternative approach to future pulsed laser deposition based high-temperature superconductor thin film and coated conductor technologies. Although the nanograined material is introduced earlier, in this work, we comprehensively demonstrate the modified ablation process, together with unconventional nucleation and growth mechanisms that produces dramatically enhanced flux pinning properties. The results can be generalized to other complex magnetic oxides, where an increased number of defects are needed for modifying their magnetic and electrical properties, thus improving their usability in the future technological challenges. [ABSTRACT FROM AUTHOR]

In order to understand how the doping with self-assembled nanorods of different sizes and concentrations as well as applied magnetic fields affect the critical current anisotropy in YBa2Cu3O7−x (YBCO) thin films close to YBCO c-axis, we present an extensive and systematic computational study done by molecular dynamics simulation. The simulations are also used to understand experimentally measured Jc(θ) curves for BaHfO3, BaZrO3 and BaSnO3 doped YBCO thin films with the help of nanorod parameters obtained from transmission electron microscopy measurements. Our simulations reveal that the relation between applied and matching field plays a crucial role in the formation of Jc(θ)-peak around YBCO c-axis (c-peak) due to vortex-vortex interactions. We also find how different concentrations of different size nanorods effect the shape of the c-peak and explain how different features, such as double c-peak structures, arise. In addition to this, we have quantitatively explained that, even in an ideal superconductor, the overdoping of nanorods results in decrease of the critical current. Our results can be widely used to understand and predict the critical current anisotropy of YBCO thin films to improve and develop new pinscapes for various transport applications. [ABSTRACT FROM AUTHOR]

Er-doped phosphate glass ceramics were fabricated by melt-quenching technique followed by a heat treatment. The effect of the crystallization on the structural and luminescence properties of phosphate glasses containing Al2O3, TiO2, and ZnO was investigated. The morphological and structural properties of the glass ceramics were characterized by Field Emission-Scanning Electron Microscopy (FE-SEM), X-ray Diffraction (XRD), and micro-Raman spectroscopy. Additionally, the luminescence spectra and the lifetime values were measured in order to study the influence of the crystallization on the spectroscopic properties of the glasses. The volume ratio between the crystal and the glassy phases increased along with the duration of the heat treatment. The crystallization of the glass ceramics was confirmed by the presence of sharp peaks in the XRD patterns and different crystal phases were identified depending on the glass composition. Sr(PO3)2 crystals were found to precipitate in all the investigated glasses. As evidenced by the spectroscopic properties, the site of the Er3+ ions was not strongly affected by the heat treatment except for the fully crystallized glass ceramic which does not contain Al2O3, TiO2, and ZnO. An increase of the lifetime was also observed after the heat treatment of this glass. Therefore, we suspect that the Er3+ ions are incorporated in the precipitated crystals only in this glass ceramic [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanorods were manufactured using the aqueous chemical growth (ACG) method, and the effect of thermal acetylene treatment on their morphology, chemical composition, and optical properties was investigated. Changes in the elemental content of the treated rods were found to be different than in previous reports, possibly due to the different defect concentrations in the samples, highlighting the importance of synthesis method selection for the process. Acetylene treatment resulted in a significant improvement of the ultraviolet photoluminescence of the rods. The greatest increase in emission intensity was recorded on ZnO rods treated at the temperature of 825 °C. The findings imply that the changes brought on by the treatment are limited to the surface of the ZnO rods. [ABSTRACT FROM AUTHOR]

The colossal magnetoresistive insulator to metal switching of almost nine orders of magnitude under the significantly reduced magnetic field is achieved by illumination for the low bandwidth manganite thin films. Similarly, by changing the measuring bias voltage through the sample the required magnetic field for insulator-metal transition can be further fine-tuned. By applying a magnetic field of suitable strength, the samples can also be tuned to be extra sensitive to the illumination having colossal effect on the resistivity at low temperatures. This kind of utilizing of multiple external stimulants, which together change the properties of the material, could have significant impact on the new generation of phase-change memories working under affordable conditions. [ABSTRACT FROM AUTHOR]

Photo-induced magnetization has been studied in small-bandwidth manganite PrCaMnO ( x = 0.1) (PCMO) bulk and thin films. It is observed that the persistent change in magnetization under optical excitation is much stronger in epitaxial thin films of PCMO compared to the bulk. This change is manifested in a change of both coercive field and Curie temperature of the thin films. Stronger photo-induced effect in the thin films might have their origin in the substrate-induced strain effect on the magnetic properties. [ABSTRACT FROM AUTHOR]

The magnetocaloric applicability of the perovskite-structured (Pr,Ca) manganite family (PCMO) was estimated based on the magnetic transition entropies of polycrystalline bulk samples. Transitions in the temperature range from 5 to 400 K were investigated in external fields up to 5 T. Earlier results published on the matter were reproduced, extended to Ca concentrations below $x = 0.2$ and up to $x = 1$ , and complemented by determining standardized refrigerant capacity estimates corresponding to the largest entropy changes detected in each sample. The quantitative agreement between the measured transition entropies and literature also served to verify a time-optimized data collection method based on quick temperature scans of magnetization at constant magnetic fields. Making use of the mathematical regularity of magnetization curves, improved time, and cryogen efficiency was arguably attained compared with a more traditional data collection method without significant loss of accuracy. The results of this paper convey a very graphical overview of the quite well established phase diagram of PCMO and promise a significant magnetocaloric effect below 150 K, possibly on par with that exhibited by Gd-based alloys around room temperature. However, little hope can be offered for the room temperature refrigeration applications of PCMO. [ABSTRACT FROM AUTHOR]

Hall coefficient, electrical conductivity, and electron mobility are investigated for n-ZnSe:Yb single crystals with high concentration of electrically active background impurities (( [ABSTRACT FROM AUTHOR]

This article presents a comparative study of persistent photo-induced magnetization in intermediate and low bandwidth perovskite manganite thin films, and analyzes the possible mechanisms for the observed differences in light of their structural and magnetic properties. Intermediate bandwidth manganite LaCaMnO (LCMO) and low bandwidth manganite PrCaMnO (PCMO), both show persistent change in magnetization under light. However, under illumination, while LCMO shows increased ferromagnetic (FM) interaction both in low and saturation field regime, PCMO shows increased FM interaction at low fields and decreased FM behavior near saturation fields. Also relaxation of photo-induced magnetization shows stretched exponential nature in LCMO compared to much faster relaxation, beyond detection limit in PCMO. Comparison between these two systems will provide important insight of the underlying physics of persistent photo-induced magnetization of perovskites manganites and will consequently facilitate their application in magneto-optical devices, photodiodes and photovoltaics. [ABSTRACT FROM AUTHOR]

High dielectric constant and its dependence on structural strain and grain boundaries (GB) in LaSrMnO (LSMO) thin films are reported. X-ray diffraction, magnetization, and magneto-transport measurements of the LSMO films, made by pulsed laser deposition on two different substrates-MgO and SrTiO (STO), were compared to co-relate magnetic properties with dielectric properties. At room temperature, in the ferromagnetic phase of LSMO, a high dielectric constant (6 × 10) was observed up to 100 kHz frequency for the films on MgO, with polycrystalline properties and more high-angle GB related defects, while for the films on STO, with single-crystalline properties but strained unit cells, high dielectric constant (≈10) was observed until 1 MHz frequency. Also, a large dielectric relaxation time with significant broadening from the Debye single-dielectric relaxation model has been observed in samples with higher GB defects. Impedance spectroscopy further shows that large dielectric constant of the single-crystalline, strained LSMO film is intrinsic in nature while that in the polycrystalline films are mainly extrinsic due to higher amount of GBs. The presence of high dielectric constant value until high frequency range rules out the possibility of 'apparent giant dielectric constant' arising from the sample-electrode interface. Coexistence of ferromagnetism and high dielectric constant can be very useful for different microelectronic applications. [ABSTRACT FROM AUTHOR]

Streptococcus suis Dpr belongs to the Dps family of bacterial and archaeal proteins that oxidize Fe to Fe to protect microorganisms from oxidative damage. The oxidized iron is subsequently deposited as ferrihydrite inside a protein cavity, resulting in the formation of an iron core. The size and the magnetic properties of the iron core have attracted considerable attention for nanotechnological applications in recent years. Here, the magnetic and structural properties of the iron core in wild-type Dpr and four cavity mutants were studied. All samples clearly demonstrated a superparamagnetic behavior in superconducting quantum interference device magnetometry and Mössbauer spectroscopy compatible with that of superparamagnetic ferrihydrite nanoparticles. However, all the mutants exhibited higher magnetic moments than the wild-type protein. Furthermore, measurement of the iron content with inductively coupled plasma mass spectrometry revealed a smaller amount of iron in the iron cores of the mutants, suggesting that the mutations affect nucleation and iron deposition inside the cavity. The X-ray crystal structures of the mutants revealed no changes compared with the wild-type crystal structure; thus, the differences in the magnetic moments could not be attributed to structural changes in the protein. Extended X-ray absorption fine structure measurements showed that the coordination geometry of the iron cores of the mutants was similar to that of the wild-type protein. Taken together, these results suggest that mutation of the residues that surround the iron storage cavity could be exploited to selectively modify the magnetic properties of the iron core without affecting the structure of the protein and the geometry of the iron core. [ABSTRACT FROM AUTHOR]

Recombination of the primary radical pair of photosystem II (PSII) of photosynthesis may produce the triplet state of the primary donor of PSII. Triplet formation is potentially harmful because chlorophyll triplets can react with molecular oxygen to produce the reactive singlet oxygen (1O2). The yield of 1O2 is expected to be directly proportional to the triplet yield and the triplet yield of charge recombination can be lowered with a magnetic field of 100–300 mT. In this study, we illuminated intact pumpkin leaves with strong light in the presence and absence of a magnetic field and found that the magnetic field protects against photoinhibition of PSII. The result suggests that radical pair recombination is responsible for significant part of 1O2 production in the chloroplast. The magnetic field effect vanished if leaves were illuminated in the presence of lincomycin, an inhibitor of chloroplast protein synthesis, or if isolated thylakoid membranes were exposed to light. These data, in turn, indicate that 1O2 produced by the recombination of the primary charge pair is not directly involved in photoinactivation of PSII but instead damages PSII by inhibiting the repair of photoinhibited PSII. We also found that an Arabidopsis thaliana mutant lacking α‐tocopherol, a scavenger of 1O2, is more sensitive to photoinhibition than the wild‐type in the absence but not in the presence of lincomycin, confirming that the target of 1O2 is the repair mechanism. [ABSTRACT FROM AUTHOR]

We report the effect of 4 wt% BZO-doping in GdBCO thin films on (100) STO substrates with novel nanograined target materials deposited by pulsed laser deposition (PLD) method. X-ray diffraction, atomic force microscopy and magnetization measurements, which were made in particularly wide temperature and magnetic field range, were used to determine the structural and superconducting properties. The results were compared with ones of YBCO. The deposition temperature, Ts, is not very critical for GdBCO and it is found to be much lower in undoped and BZO-doped GdBCO than in YBCO. The BZO-doping of GdBCO enhanced the field dependence of critical current density, jc, at low temperatures. Furthermore, BZO-doping enhances the accommodation field, B*, below 60 K being clearly higher at 10 K in doped GdBCO than in YBCO. The pinning mechanism in GdBCO was concluded to be similar to that of YBCO. Our results clearly show that undoped and BZO-doped nanophase GdBCO is a very promising target material for applications as well as for coated conductors. [ABSTRACT FROM AUTHOR]

The accommodation field, B*, is generally defined to be the field at which the cross over from single vortex pinning to collective pinning occurs. It is determined from magnetization curves as the point where the Jc plateau ends and it used as a convenient way of comparing the pinning properties of superconducting films. Similarly, the characteristic field, Bc, can be obtained from magneto-optical (MO) images from when the flux fronts meet in the middle of the film. The matching field, Bc at which there is one vortex line per pinning site, is sometimes thought to be the same as B*, but in BaZrO3-doped YBa2Cu3O7 films the calculated BΦ, is much higher than the observed B*. BΦ, can be determined from angular dependent transport measurements. All of the field values correspond to some special case in the flux pinning in the film and relate to Jc. In this work we have determined Bc, B * and BΦ, for different kinds of YBCO films using MO, magnetization and transport measurements to reveal the deeper meaning of the special fields. [ABSTRACT FROM AUTHOR]

Superconducting YBa2Cu3O6+x (YBCO) films are grown by pulsed laser deposition (PLD) in the orientation where its c-axis is lying in the plane of the film using (110) oriented SrTiO3 (STO) substrates with PrBCO template layer. By optimization of deposition temperature and rate the easily formed (103) orientation was avoided to get smooth and completely (110) oriented YBCO films. To improve the superconducting properties, we have also optimized the BaZrO3 (BZO)-doping in the (110) YBCO films. This gives the possibility to apply the current along the YBCO CuO2 planes where the critical current is much higher in thin film multilayers or to investigate the anisotropy and the effect of BZO pinning structure in different film orientations. [ABSTRACT FROM AUTHOR]

Studies thermally induced motion and clustering of single particles obtained by pulsed laser deposition (PLD) from uniform size Y-Ba-Cu-O superconducting thin films. Average height and radius of particles after annealing at different temperatures; Dependence of the average height and radius of the particles on temperature.

Keywords: dosimetry; imaging; photochromism; sodalite; X-ray detection EN dosimetry imaging photochromism sodalite X-ray detection 1 1 1 10/20/21 20211018 NES 211018 Hackmanites are a family of optically intelligent materials having the ability for reversible photochromism upon X-ray exposure. Dosimetry, imaging, photochromism, sodalite, X-ray detection In article number 2100762, Mika Lastusaari, Tangui Le Bahers and co-workers elucidate how X-rays induce the pairing of electrons and holes to form eraseable color centers in these materials. [Extracted from the article]

We have prepared YBCO nanopowder by the sol-gel route. The original powder contains weak links as observed by magnetization and microwave absorption measurements. Most of the weak links could be reduced by keeping the powder in ethanol for 30 min in an ultrasonic bath. It was also found that the ultrasonic bath does not affect the superconducting properties of the nanoparticles themselves. The modulation field applied in the microwave absorption measurements was found to have a large effect on the temperature dependence of the absorption. This phenomenon was explained with a phase diagram for the weak links. [ABSTRACT FROM AUTHOR]

Striving to improve the critical current density Jc of superconducting YBa2Cu3O6+x (YBCO) thin films via enhanced vortex pinning, the interplay between film growth mechanisms and the formation of nanosized defects, both natural and artificial, is systematically studied in undoped and BaZrO3 (BZO)-doped YBCO thin films. The films were grown via pulsed laser deposition (PLD), varying the crystal grain size of the targets in addition to the dopant content. The microstructure of the PLD target has been observed to have a great impact on that of the deposited thin films, including the formation of vortex pinning centers, which has direct implications on the superconducting performance, especially on the isotropy of flux pinning properties. Based on experimentally measured angular dependencies of Jc, coupled with a molecular dynamics (MD) simulation of flux pinning in the YBCO films, we present a quantitative model of how the splay and fragmentation of BZO nanorods artifically introduced into the YBCO film matrix explain the majority of the observed critical current anisotropy. [ABSTRACT FROM AUTHOR]

The formation of superconducting nanocomposites from preformed nanocrystals is still not well understood. Here, we examine the case of ZrO2 nanocrystals in a YBa2Cu3O7−x matrix. First we analyzed the preformed ZrO2 nanocrystals via atomic pair distribution function analysis and found that the nanocrystals have a distorted tetragonal crystal structure. Second, we investigated the influence of various surface ligands attached to the ZrO2 nanocrystals on the distribution of metal ions in the pyrolyzed matrix via secondary ion mass spectroscopy technique. The choice of stabilizing ligand is crucial in order to obtain good superconducting nanocomposite films with vortex pinning. Short, carboxylate based ligands lead to poor superconducting properties due to the inhomogeneity of metal content in the pyrolyzed matrix. Counter-intuitively, a phosphonate ligand with long chains does not disturb the growth of YBa2Cu3O7−x. Even more surprisingly, bisphosphonate polymeric ligands provide good colloidal stability in solution but do not prevent coagulation in the final film, resulting in poor pinning. These results thus shed light on the various stages of the superconducting nanocomposite formation. [ABSTRACT FROM AUTHOR]