We have studied the influence of BaZrO3 nanoinclusions on the local structure and critical current density of second-generation high temperature superconducting tapes based on YBa2Cu3O7−δ (YBCO) films. The films were made by metal–organic chemical vapor deposition (MOCVD). The crystal and local structure of the materials under study were analysed by x-ray diffraction and x-ray absorption spectroscopy (EXAFS + XANES). We have found that, being added at MOCVD process, Zr forms BaZrO3 nanoinclusions in YBCO matrix. The distance between Zr and the neighboring atoms is shorter than that one in a bulk crystalline BaZrO3, so we conclude that the nanoinclusions are in compressed state. The incorporation of 5 mol% BaZrO3 minimizes the static disorder of Cu–O bonds and maximizes their stiffness in YBCO. We show that the local structure peculiarities correlate well with the observed critical current behavior and consider this to be additional evidence in favor of small amounts of BaZrO3 nanoinclusions as efficient pinning centers.

Thin films of in-bulk unstable multiferroic hexagonal LuFeO 3 were synthesized on coherent (111) and for the first time on incoherent (100) YSZ and Pt/ YSZ surfaces by the metal−organic chemical vapor deposition (MOCVD) technique. The obtained films were thoroughly studied by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), atomic force microscopy (AFM), piezoresponse force microscopy (PFM), and theoretical simulations. The substrate surface symmetry has a crucial role in the formation of the epitaxial film's structure. Also, the molecular mechanics calculations were adapted for film/substrate interface simulation and, for the first time, the number of variants was predicted by the number of minima on the energy profile as well as it was proved that that the formation of h-LuFeO 3 is more energetically preferable than o-LuFeO 3 , even on the incoherent surface. It was shown that h-LuFeO 3 films deposited on the YSZ(111) surface have formed a single in-plane rotational variant structure, while those deposited on the YSZ(100) surface have formed a bivariant structure. PFM results of bivariant h-LuFeO 3 (001)//Pt(111)//YSZ(100) show half the size of ferroelectric domains (∼100 nm) and twice as large the values of piezoelectric response compared to h-LuFeO 3 (001)//Pt(111)//YSZ(111).

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