238000005755 formation reaction Methods 0.000 title description 7.230000015572 biosynthetic process Effects 0.000 title description 7.239000002244 precipitate Substances 0.000 title abstract description 39.Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) Filing date Publication date Application filed by Russell J Horst filed Critical Russell J Horst Priority to US84655669A priority Critical Application granted granted Critical Publication of US3579443A publication Critical patent/US3579443A/en Anticipated expiration legal-status Critical Status Expired - Lifetime legal-status Critical Current Links Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired - Lifetime Application number US846556A Inventor Russell J Horst Original Assignee Russell J Horst Priority date (The priority date is an assumption and is not a legal conclusion. Google Patents Formation of dense precipitatesĭownload PDF Info Publication number US3579443A US3579443A US846556A US3579443DA US3579443A US 3579443 A US3579443 A US 3579443A US 846556 A US846556 A US 846556A US 3579443D A US3579443D A US 3579443DA US 3579443 A US3579443 A US 3579443A Authority US United States Prior art keywords iron precipitate water bed vessel Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google Patents US3579443A - Formation of dense precipitates A possible mechanism of precipitate formation is proposed.US3579443A - Formation of dense precipitates The use of off-axis polished substrates could successfully suppress the nucleation of the precipitates. The film-thickness dependences of the precipitate density and size were quantitatively analyzed by scanning electron microscopy to indicate that the nucleation of precipitates occurred by the initial 50 nm growth of the film to be followed by the increase of the precipitate’s size. Under such thermodynamically off-equilibrated conditions, the phase separation into YBCO and secondary phases is presumed to be kinetically prevented to give solid-soluted films and off-stoichiometric compositions and inferior crystallinity and superconductivity. The precipitate formation was reduced when the films were grown under conditions slightly deviated from the optimum for the formation of well-equilibrated, highly crystalline, and high- T c and high- J c films. The coexistence of these two phases with a YBCO matrix film is well explained by the pseudoternary phase diagram of YO 1.5-BaO-CuO, assuming a slight Y deficiency in the film. Scanning-Auger-electron spectroscopy identified two types of precipitates, i.e., BaCuO 2 and CuO, on the films deposited from a stoichiometric YBCO target. We have investigated systematically the particle formation on the surface of high-quality YBa 2 Cu 3 O 7 − δ (YBCO) epitaxial films grown by pulsed laser deposition.
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