Technology of production of barium-lanthanum cuprate

With the help of glycine-nitrate technology, nanoparticles of barium-lanthanum cuprate complex oxide were obtained and its properties were studied. According to x-ray phase analysis, the synthesized sample is single-phase.The complex oxide has a perovskite structure with the spatial group Pmmm (47). The parameters of the crystal lattice calculated from the diffractogram are determined. The microstructure of the obtained compositions was determined by scanning electron microscopy. The sample has a porous foam-like microstructure, consists of aggregates having a size of 15-98 nm. Using thermal analysis, it was found that during heating the mass of the sample was lost (4.19%). The greatest loss of mass is observed in the range 318-372 °C, the process is accompanied by an endothermic effect, which corresponds to the loss of bound water, which was sorbed into the pores and entered the structure of the complex oxide. The possibility of the perovskite layered structure to intercalate water and ions into the interlayer space, the structure of which is a "nanoreactor" for further chemical transformations, is confirmed. The enthalpy of deintercolation corresponds to 2.052 kJ/mol, this value correlates with the enthalpy values of deintercolation for perovskite structures (1.5-17.0 kJ/mol). The technology can be applied to solve practical problems of synthesis of nanopowders of mixed oxides as import-substituting components of automotive catalysts and promising ceramic materials with specified functional properties.

High-temperature superconductivity at the lanthanum cuprate/lanthanum–strontium nickelate interface

Local ionic and electronic redistribution occurs at the lanthanum cuprate/lanthanum nickelate epitaxial contact and gives rise to a high-temperature superconducting layer.