Single Source Precursor for PAD-LaMnO3 Thin Films

A new lanthanum and manganese ethylenediaminetetraacetate (EDTA) coordination polymer (EDTA4− = [(CH2N)2(CH2-COOH)(CH2COO)4]) was synthesized from La(NO3)3 and Mn(NO3)2 reagents, ethylenediaminetetraacetic acid, and water at room temperature. The structure of the new compound formed, [{La2Mn3(EDTA)3(H2O)11}·12H2O]n, was determined by the single crystal X-ray diffraction technique. The synthesis and characterization of the La(III) and Mn(II) coordination complex, characterized by FTIR spectroscopy, thermogravimetry, and differential thermal analysis of the complex, are envisaged. X-ray crystal structure determination indicates that seven- and four-coordinate modes between La(III)/Mn(Π) and H4EDTA exist. [{La2Mn3(EDTA)3(H2O)11}·12H2O]n crystallizes in the monoclinic space group C2 with unit cell parameters of a = 16.1227(17) Å, b = 14.8049(16) Å, c = 14.8736(16) Å, and β = 116.107(2)°. Using this precursor, LaMnO3 (LMO) epitaxial thin films were grown by the polymer-assisted deposition (PAD) method on (100)SrTiO3 (STO) single crystalline substrates at a temperature of 900 °C. The LMO crystallized films exhibit a (001)LMO/(001)STO out-of-plane epitaxial relationship and a smooth surface morphology

Development of a Fluorine-Free Polymer-Assisted-Deposition Route for YBa2Cu3O7−x Superconducting Films

Polymer assisted deposition (PAD) was used as an environmentally friendly, non-fluorine, growth method for superconducting YBa2Cu3O7−x (YBCO) films. The kinetics of the thermal decomposition of the precursor powder was studied by thermogravimetry coupled with mass spectrometry (TG-QMS). YBCO films were spin coated on (100) SrTiO3 (STO) single crystalline substrates, followed by a single step thermal treatment under wet and dry O2 and O2/N2 mixture. The as-obtained films were epitaxially grown having a [001]YBCO||[001]STO out-of-plane epitaxial relationship and exhibited good superconducting properties with Tc (R = 0) > 88 K, transition widths, ΔT ≈ 2 K and critical current densities as high as 2.3 MA/cm2 at 77 K and self magnetic field

Development of a Fluorine-Free Polymer-Assisted-Deposition Route for YBa2Cu3O7−x Superconducting Films

Polymer assisted deposition (PAD) was used as an environmentally friendly, non-fluorine, growth method for superconducting YBa2Cu3O7−x (YBCO) films. The kinetics of the thermal decomposition of the precursor powder was studied by thermogravimetry coupled with mass spectrometry (TG-QMS). YBCO films were spin coated on (100) SrTiO3 (STO) single crystalline substrates, followed by a single step thermal treatment under wet and dry O2 and O2/N2 mixture. The as-obtained films were epitaxially grown having a [001]YBCO||[001]STO out-of-plane epitaxial relationship and exhibited good superconducting properties with Tc (R = 0) > 88 K, transition widths, ΔT ≈ 2 K and critical current densities as high as 2.3 MA/cm2 at 77 K and self magnetic field.This work was supported by MRI-UEFISCDI through PN-III-P1-1.1-TE-2016-2465-SuperMagSense contract No. 80/02.05.2018, project 21 PFE-2018 and contract No. 1991 Internal Competition CICDI-2017.Peer reviewe

Morphological and Structural Evolution of Chemically Deposited Epitaxially LaNiO3 Thin Films

We report the preparation and characterization of epitaxial LaNiO3 (LNO) thin films by chemical solution deposition method using lanthanum and nickel acetylacetonates as starting reagents dissolved in propionic acid. In order to obtain further information regarding the decomposition behavior of the film, the precursor solution was dried to obtain the precursor powder, which was investigated by thermal analyses and X-ray diffraction measurements (XRD). The LNO perovskite thin films were deposited by spin coating on SrTiO3(100) single crystal substrates. A detailed study with different crystallization temperatures (600–900 °C) at two different heating ramps (5 and 10 °C/min) was performed. Oriented LaNiO3 thin films with good out-of-plane textures were obtained with optimal surface morphologies

Hydrothermal Deposition of ZnO Layer on Fe-Based Amorphous Fibres Used for the Preparation of Cold Sintered Fibre-Based Soft Magnetic Composites

This paper presents findings on the influence of hydrothermal deposition processing parameters (precursor concentration and deposition duration) on the characteristics of ZnO layers deposited on the surface of amorphous Fe-based fibres. The characteristics of the coated fibres, especially the deposited layer, were investigated from structural, morphological, chemical, thermal and magnetic points of view. It was found that the use of a zinc acetate-based solution of 0.05 M concentration and a deposition duration of 24 h leads to a continuous, thin and adherent layer of ZnO on the surface of the fibres. The thickness of the ZnO layer is 450–500 nm, as shown by TEM-EDX investigations. The ZnO coated fibres were used to prepare fibre-based soft magnetic composites via a cold sintering process. The composites obtained are the first reported soft magnetic composites based on amorphous fibres. The coercive field of the cold sintered composites is 3.5 to 8.6 times lower, and the maximum relative permeability is 2.4 times larger, than the best coercive field and the maximum relative permeability reported until now for a crystalline fibre-based soft magnetic composite. The initial relative permeability of cold sintered composites is constant up to the frequency of 1000 Hz

Single Source Precursor for PAD-LaMnO3 Thin Films

A new lanthanum and manganese ethylenediaminetetraacetate (EDTA) coordination polymer (EDTA4− = [(CH2N)2(CH2-COOH)(CH2COO)4]) was synthesized from La(NO3)3 and Mn(NO3)2 reagents, ethylenediaminetetraacetic acid, and water at room temperature. The structure of the new compound formed, [{La2Mn3(EDTA)3(H2O)11}·12H2O]n, was determined by the single crystal X-ray diffraction technique. The synthesis and characterization of the La(III) and Mn(II) coordination complex, characterized by FTIR spectroscopy, thermogravimetry, and differential thermal analysis of the complex, are envisaged. X-ray crystal structure determination indicates that seven- and four-coordinate modes between La(III)/Mn(Π) and H4EDTA exist. [{La2Mn3(EDTA)3(H2O)11}·12H2O]n crystallizes in the monoclinic space group C2 with unit cell parameters of a = 16.1227(17) Å, b = 14.8049(16) Å, c = 14.8736(16) Å, and β = 116.107(2)°. Using this precursor, LaMnO3 (LMO) epitaxial thin films were grown by the polymer-assisted deposition (PAD) method on (100)SrTiO3 (STO) single crystalline substrates at a temperature of 900 °C. The LMO crystallized films exhibit a (001)LMO/(001)STO out-of-plane epitaxial relationship and a smooth surface morphology

Investigation of diethanolamine (DEA) as a chelating agent in the fabrication of fluorine-free propionate route YBa2Cu3O7 (YBCO) thin films

The role of diethanolamine (DEA) as a chelating agent was investigated in a fluorine-free precursor solution for the growth of superconducting YBa2Cu3O7 (YBCO) thin films via chemical solution deposition. Infrared spectroscopy and thermal analyses were employed to elucidate the interactions between the chelating agent and propionate-based coating solution. The physical properties of the as-obtained YBCO films were investigated to assess the effect of DEA addition on film growth. Special emphasis was placed on the determination of superconducting transport properties. These have been investigated in wide magnetic field (0-18 T) and temperature (4.5-77 K) ranges to account for various possible application scenarios. The 100 nm thick YBCO film deposited on a (001) SrTiO3 single-crystal substrate exhibited a critical current density of 4 MA cm-2 at 77 K in self-field.This work was carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom program 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. A D acknowledges the financial support of the 'Entrepreneurial skills and research excellence in doctoral and postdoctoral programs -ANTREDOC'—POCU/380/6/13/123927 project. M N and T P Jr acknowledge the financial support of a grant of the Romanian Ministry of Education and Research, CNCS-UEFISCDI, project number PN-III-P1-1.1-TE-2021-1777, within PNCDI III.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Microwave Measurements of Pinning Properties in Chemically Deposited YBCO/BZO Films

We present a comparative study of vortex pinning in chemically deposited YBaO nanocomposite films, with the aim of correlating the preparation method to the superconducting properties. Two sets of samples have been prepared by different low fluorine routes (one set followed the in situ approach), with different starting YBCO coating solution and with a different amount of BaZrO. The short-range vortex pinning properties have been assessed using a contactless microwave (48 GHz) technique, which yielded the vortex pinning constant (Labusch parameter) and the vortex viscosity as a function of the applied field up to 0.8 T, and for temperatures between 60 K and. The results were compared to more usual (long-range vortex motion) measurements. Despite the supposed similarity in pinning as determined from, we found significant differences between the pinning properties of the two sets of samples. It appears that the in situ approach results in stronger pinning at microwaves in the whole temperature range explored, and that this behavior is due to the smaller dimensions of BaZrO nanoparticles. This information can be very useful in the search of optimized chemical route to strong pinning superconducting nanocomposite materials

Surface decoration as a prospective artificial pinning strategy in superconducting YBa2Cu3O7x films

This study investigates chemically decorated surfaces as tools for the improvement of transport properties in superconducting YBa2Cu3O7xfilms. This approach, still to be thoroughly investigated, makes use of low-cost easily tunable chemical methods to obtain self-assembled oxide nanostructures on a substrate that will serve, in a second step, for the deposition of the superconducting film itself. The structures are supposed to produce in the superconducting matrix a specific amount of strain, which is generally held responsible for the increased transport capacity of variously doped samples. For the growth of the nanostructures, two different methods have been employed: Polymer-assisted deposition and metal-organic decomposition (MOD). The main advantages and disadvantages of these two routes are discussed. The oxide chosen for the deposition is one commonly used for artificial pinning in YBa2Cu3O7x, namely Ba2YNbO6, together with the less common but highly interesting ferromagnetic compound La0,77Sr0,33MnO3. We also show how the density of these nanostructures can be easily controlled, and the necessary requirements for the growth of nanostructures are determined. A variety of crystalline substrates were tested for the deposition of the nanoparticles, such as SrTiO3, YSZ, MgO. YBa2Cu3O7x films have been deposited on selected samples via standard low-fluorine MOD and characterized scanning electron microscopy (SEM), x-ray diffraction (XRD), vibrating sample magnetometer (VSM), direct current (DC) resistivity, and critical current measurements. The presence of the nanostructures results, in this case, in a slight increased value of Jc, which can be ascribed to the relatively low density of nanoparticles