(119) Bi-2223 thin films grown by MOCVD on (100) NdGaO3 and (110) SrTiO3

In high temperature superconductors (HTS) the coherence length along non-c axis directions is longer. This feature can be useful when designing electronics devices based on HTS. Therefore growth and characterization of non-c axis oriented thin HTS films is of great interest. In this paper we present a short review of our data regarding (119) Bi-2223 thin films grown by MOCVD on (100) NdGaO3 and (110) SrTiO3. The emphasis is made on improvement and control of the quality of the films by the "two-temperature" technological approach and/or use of the vicinal substrates. Phase and morphology evolution for different processing conditions, substrate's type and off-angle are presented. The highest critical temperatures of T-c0=67.2 K and T-c0=74 K for the "single-" and "two-" temperature routes were obtained on vicinal SrTiO3 with the off-angle of 20degrees. A higher off-angle promoted the formation of a specific step-like morphology with lower roughness. For the films grown on flat substrates the morphology was of mountain-range shape. Surface morphology as a result of two types of growth mechanisms (two-dimensional (2D), assisted by a so-called "twin"-growth and step-flow growth) for the (119) Bi-2223 films are discussed.