This paper discusses the design of an input multiplexer for satellite applications. The channel filters are self equalised eight pole high temperature superconductor (HTS) planar structures. Measured ...data shows the feasibility of this filter realisation with the cross loop resonators. A new configuration is proposed to annihilate the parasitic coupling and to obtain a compact structure. In this case, the responses are improved.
Using a “two-steps” synthesis mode, the homogeneity ranges of the perovskites Ln1 - x Ba x MnO3 were extended up to x = 0.60 for the Pr-based samples and x = 0.50 for the La ones. Two new ...perovskites, a cubic form and a P-type tetragonal phase (with a C × a C × 2a C parameters) have been isolated. The HREM study shows a nanostructural behavior of the new tetragonal form, only stabilized in small domains. These compounds exhibit a ferromagnetic metallic to paramagnetic insulating transition at increasing temperature, over a large homogeneity range, independent of the nature of the perovskite structure. Consequently, magnetoresistance effects are observed. The Curie temperature reaches values as high as 362 K and goes though a maximum. These properties are discussed considering three factorssize, valence, and mismatch effectswhich are known to govern the CMR properties of the manganites.
In the mid-infrared absorption of Sr{1-x}Ce{x}MnO{3} at low electron doping (x = 0.05), a band at 0.3 eV is fully replaced by another one at 0.9 eV as the system becomes antiferromagnetic (AF) of ...type \(G\). A weaker effect occurs at x = 0.10 for an AF phase of type \(C\). One thus directly measures the electron hopping energies for spin parallel and anti-parallel to that of the host ion. The Hund's, crystal-field, and Jahn-Teller splittings for the Mn{3+} ions in a Mn{4+} matrix, can also be derived.
We report a detailed study of step-like metamagnetic transitions in the
magnetization and resistivity of polycrystalline Pr0.5Ca0.5Mn0.95Co0.05O3. The
steps have a sudden onset below a critical ...temperature, are extremely sharp
(width < 0.2 mT), and occur at critical fields which are linearly dependent on
the absolute value of the cooling field in which the sample is prepared.
Similar transitions are also observed at low temperature in non-Co doped
manganites, including single crystal samples. These data show that the steps
are an intrinsic property, qualitatively different from either previously
observed higher temperature metamagnetic transitions in the manganites or
metamagnetic transitions observed in other materials.
