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Structure and transport properties of Eu-doped YBa2-xEuxCu3O7-δ (YBECO) have been studied. Eu is confirmed preferring to replace Ba at Ba sites. The averaged valence state of Eu, which is examined by x-ray photoemission spectroscopy, increases with increasing x. Eu doping in YBECO has a little influence on superconductivity in our studies, and the superconducting transition temperature Tc is almost unchanged. [ABSTRACT FROM AUTHOR]

With varying the content of Ca, single phase of La0.7Ca0.3-xMnO3 (LCMO) with Pnma symmetry have been studied. There is no phase transition detected with varing the content of Ca. The divergence of Mn-O1(ax) and Mn-O2(eq) values indicates the occurrence of lattice distortions. No marked variations of Mn-O1-Mn and Mn-02-Mn bond angles are observed. The insulator-metal transition temperature TMI of samples shifts to lower values with increasing vacancy content. At low temperature region, a large MR (30∼45%) is observed. We attribute it to the grain boundary tunnel effect. [ABSTRACT FROM AUTHOR]