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The achievement of high critical currents in ‘all-chemical’ YBa2Cu3O7−δ thick films from low cost and versatile chemical solution deposition (CSD) methodology is still an open issue. Here we report a study of the nucleation and growth conditions to achieve YBa2Cu3O7−δ films in excess of 1 micron using single pass inkjet printing or multideposition of low-fluorine metalorganic precursors. Growth conditions of thick YBa2Cu3O7−δ layers are first investigated on LaAlO3, where there is no interfacial chemical reactivity. The second architecture investigated is an ‘all-chemical’ CSDCe0.9Zr0.1O2(CZO)/YSZ multilayer on single crystal substrates which serves as model system for coated conductors. Finally, the ‘all-chemical’ coated conductor architecture CSDYBa2Cu3O7/CSDCZO/ABADYSZ/stainless steel, where ABAD stands for alternating beam assisted deposition, is investigated. The nucleation conditions of YBa2Cu3O7−δ films on top of CΖΟ cap layers have been selected to minimize the formation of the BaCeO3 phase at the interface. We demonstrate that by combining the use of Ag additives in the starting YBCO solution and processing conditions leading to low supersaturation (high water pressure and low temperature) we can achieve ∼1 μm thick YBa2Cu3O7−δ films and coated conductors with high critical currents of  = 390 and 100 A/cm-w, respectively, at 77 K and self-field. The achieved control of the interfacial reactivity with CeO2 cap layers opens a route for further increasing film thickness and critical currents in ‘all-chemical’ YBa2Cu3O7−δ coated conductors.

The electrical properties of random networks of single-wall carbon nanotubes (SWNTs) obtained by inkjet printing are studied. Water-based stable inks of functionalized SWNTs (carboxylic acid, amide, poly(ethylene glycol), and polyaminobenzene sulfonic acid) were prepared and applied to inkjet deposit microscopic patterns of nanotube films on lithographically defined silicon chips with a back-side gate arrangement. Source-drain transfer characteristics and gate-effect measurements confirm the important role of the chemical functional groups in the electrical behavior of carbon nanotube networks. Considerable nonlinear transport in conjunction with a high channel current on/off ratio of approximately 70 was observed with poly(ethylene glycol)-functionalized nanotubes. The positive temperature coefficient of channel resistance shows the nonmetallic behavior of the inkjet-printed films. Other inkjet-printed field-effect transistors using carboxyl-functionalized nanotubes as source, drain, and gate electrodes, poly(ethylene glycol)-functionalized nanotubes as the channel, and poly(ethylene glycol) as the gate dielectric were also tested and characterized.

Superconducting nanocomposites are the best material choice to address the performances required in power applications and magnets working under high magnetic fields. However, it is still challenging to sort out how to achieve the highest superconducting performances using attractive and competitive manufacturing processes. Colloidal solutions have been recently developed as a novel and very promising low-cost route to manufacture nanocomposite coated conductors. Well dispersed and stabilized preformed nanoparticle solutions are first prepared with high concentrations and then mixed with the YBa 2 Cu 3 O 7 metalorganic precursor solutions to generate colloidal solutions to grow the nanocomposite films. Here we demonstrate, for the first time, that non-reactive BaZrO 3 and BaHfO 3 perovskite nanoparticles are suitable for growing high quality thin and thick films and coated conductors with a homogeneous distribution and controlled particle size. Additionally, we extend the nanoparticle content of the nanocomposites up to 20-25 % mol without any degradation of the superconducting properties. Thick nanocomposite films, up to 0,8 µm, have been prepared with a single deposition of low-fluorine solutions using an Ink-Jet Printing dispenser and we demonstrate that the preformed nanoparticles display only a very limited coarsening during the growth process and so high critical current densities J c (B) under high magnetic fields. These films show the highest critical currents achieved so far based on the colloidal solution approach, I c = 220 A/cm-w at 77 K and self-field, and they still have a high potential for further increase of the film thickness. Finally, we also show that nanocomposite YBa 2 Cu 3 O 7-BaZrO 3 coated conductors based on Alternating Beam Assisted Deposited YSZ buffer layer on Stainless Steel metallic substrates can be developed based on these novel colloidal solutions. Non-reactive preformed oxide perovskite nanoparticles are therefore very promising elements to further advance the colloidal solution approach in the implementation of low-cost and high-performance coated conductors for high magnetic field applications.

In the present work, two kinds of hybrid polymeric-inorganic coatings containing TiO or SiO particles and prepared starting from two commercial resins (Alpha®SI30 and Bluesil®BP9710) were developed and applied to two kinds of mortars (an air-hardening calcic lime mortar [ALM] and a natural hydraulic lime mortar [HLM]) to achieve better performances in terms of water repellence and consequently damage resistance. The two pure commercial resins were also applied for comparison purposes. Properties of the coated materials and their performance were studied using different techniques such as contact angle measurements, capillary absorption test, mercury intrusion porosimetry, surface free energy, colorimetric measurements and water vapour permeability tests. Tests were also performed to determine the weathering effects on both the commercial and the hybrid coatings in order to study their durability. Thus, exposures to UV radiation, to UV radiation/condensed water cycles and to a real polluted atmospheric environment have been performed. The effectiveness of the hybrid SiO based coating was demonstrated, especially in the case of the HLM mortar.