Jonas Feys

Chemical solution deposition using ink-jet printing for YBCO coated conductors

This paper reports the successful application of ink-jet printing to the deposition of both continuous coatings and multi-filamentary structures of YBCO. Stable inks have been prepared using both the established TFA-MOD route and novel fluorine-free precursors with appropriate rheological properties for ink-jet printing. Continuous and well textured coatings with lengths exceeding 100?m and a thickness of 0.5??m have been deposited by electromagnetic ink-jet printing from TFA precursors on LZO-buffered Ni?W substrates and samples have achieved a Jc around 1.5?MA?cm?2 (self-field, 77?K). On single crystal substrates, continuous coatings and multi-filamentary structures have been deposited using piezoelectric ink-jet printing both from TFA-?and water-based precursors, achieving Jc values up to 3?MA?cm?2.

Comments on the wetting behavior of non-porous substrates for ceramic coated-conductor applications

This work gives an overview of the possibilities to improve the wetting behavior of precursors for coated conductors on non-porous substrates. Within this work, all coatings were performed on a metallic Ni–W/La2Zr2O7/CeO2 substrate using water-based Y, Ba, Cu containing precursors. The results described in this paper can be used for different technologies of chemical solution deposition, as there are ink jet printing, dip coating, spin coating etc. Starting from the forces involved during wetting, a separation between solid and liquid modifications was made. This study revealed that if a good cleaning procedure of the substrate, whether or not combined with a targeted modification of the precursor is applied, water-based solutions can be used without restriction towards their wetting behaviour leading to a sustainable technology within the coating industry. Within this work, special attention is given to (1) fast determination of the substrate cleaning procedure quality by the creation of wetting envelopes and (2) the use of a screening design of experiment to study the effects of intrinsic solution factors, such as precursor formulation, influencing the coating behavior. All modification discussed are expandable to all kinds of precursors and substrates.

A Water-Based Sol-Gel Precursor for Deposition of Thin La2Zr2O7 Layers on Ni-W Substrates

Through dip-coating Ni-5%W substrates in a water-based sol-gel solution, thin films of La₂Zr₂O₇ (LZO) were produced. This method yields highly crystalline and epitaxial films. The surface of the LZO film was found to be smooth and homogeneous. Subsequently, CeO₂ layers followed by an YBa₂Cu₃O_7-y layer were deposited via Pulsed Laser Deposition (PLD) onto the LZO film. The crystallinity and biaxial texture of the LZO layer was successfully transferred to the next layers, as demonstrated by pole figures and RHEED measurements. Resistive T_c-measurements were carried out on these samples and showed a T_c of 85 K.

A Water-Based Sol-Gel Precursor for Deposition of Thin Layers on Ni-W Substrates

Through dip-coating Ni-5%W substrates in a water-based sol-gel solution, thin films of La₂Zr₂O₇ (LZO) were produced. This method yields highly crystalline and epitaxial films. The surface of the LZO film was found to be smooth and homogeneous. Subsequently, CeO₂ layers followed by an YBa₂Cu₃O_7-y layer were deposited via Pulsed Laser Deposition (PLD) onto the LZO film. The crystallinity and biaxial texture of the LZO layer was successfully transferred to the next layers, as demonstrated by pole figures and RHEED measurements. Resistive T_c-measurements were carried out on these samples and showed a T_c of 85 K.

Chemical solution deposition of functional ceramic coatings using ink-jet printing

Abstract This paper discusses the development of environmentally-friendly precursor inks suited for ink-jet printing of functional ceramic coatings. We synthesized superconducting materials, SrTiO3 thin films for coated conductor applications and transparent TiO2 photocatalytic coatings. Here, we discuss all aspects of ink formulation, including the stabilization of metal ions, nanoparticle inks or combination of both. This demands the investigation and determination of the inks rheological parameters. Ceramic nanoparticles are often incorporated in our inks to decrease thermal processing temperatures (e.g., TiO2 or YSZ coatings...) or enhance the properties of the functional ceramic coating (e.g., pinning centres in superconducting coatings). These ceramic nanoparticles (ZrO2, HfO2, TiO2...) are synthesized through methods based on microwave heating from aqueous and/or organic solutions. With that, we aim at developing smart and environmentally friendly processes that require lower energy input.

A Water-Based Sol-Gel Precursor for Deposition of Thin

Through dip-coating Ni-5%W substrates in a water-based sol-gel solution, thin films of La₂Zr₂O₇ (LZO) were produced. This method yields highly crystalline and epitaxial films. The surface of the LZO film was found to be smooth and homogeneous. Subsequently, CeO₂ layers followed by an YBa₂Cu₃O_7-y layer were deposited via Pulsed Laser Deposition (PLD) onto the LZO film. The crystallinity and biaxial texture of the LZO layer was successfully transferred to the next layers, as demonstrated by pole figures and RHEED measurements. Resistive T_c-measurements were carried out on these samples and showed a T_c of 85 K.