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Investigating the irreversible properties of the Tl-1223 thick films with Y-123 coated conductors and Bi-2223 tapes obtained by dc transport measurement is discussed. It is concluded that the critical current density in the films is not limited by grain boundaries due to their excellent texture.

Investigating the fabrication of MgB2 thick films on different substrates using a simple screen-printing method is discussed. It is concluded that the critical current densities are dependent only modestly on the external field.

Electrical resistance R , heat capacity C , ac susceptibility, and magnetic moment of orthorhombic La0.85Ag0.15MnO3 ceramic were investigated in magnetic fields with flux density up to 5 T and in high hydrostatic pressures up to 0.9 GPa. Sharp lambda-like anomalies in R(T) and C(T) indicate ferromagnetic (FM)–paramagnetic transition. Magnetic field shifts these anomalies to higher temperature and smears them out confirming FM origin of the ordering. Magneto-resistance is negative and large reaching maximal value of about 70% for field with flux density of 5 T at the magnetic phase transition. The magnetic phase transition is accompanied with anomalies at 219.5 K in \chi '(T) and at 221 K in increases with applied pressure with the rate dT_{C}/dp=14.2 K/GPa. Magnetocaloric effect was evaluated from the magnetic entropy change \Delta S , which was determined independently from heat capacity and magnetic moment measurements. The maximal values were obtained for \mu 0 \Delta H=5 T and both values -\Delta S=5.85 Jkg ^-1 K ^-1 (heat capacity) and $-\Delta S=5.80$ Jkg ^-1 K ^-1 (magnetic moment) are comparable. Hydrostatic pressure of 0.84 GPa leads to an enhancement of $-\Delta S$ approximately about 14%. [ABSTRACT FROM AUTHOR]

Gibbs energies of transfer of the cations Li+, Na+, K+, Rb+, Cs+, Ag+, Tl+, Ba2+, Cu2+, Cd2+, Pb2+ and Hg2+ from water as reference into up to 42 non-aqueous solvents were analyzed by a statistical procedure based on the spectral theorem. The data set had to be separated into three groups. The first group included the alkali metal cations and Ba2+, the second Tl+, Cd2+ and Pb2+ and the third group Ag+ and Hg2+. Analysis of the respective subgroups yielded classification schemes for solvents versus the individual groups of cations. The respective solvent parameters derived from statistical analysis for the subgroups did not depend on each other. Correlations with solvent parameters claiming to account for "solvent softness" were only found for the parameters derived from the subgroup consisting of Ag+ and Hg2+. A mere separation into "hard and soft solvents" was found to be insufficient to account for the experimental data. [ABSTRACT FROM AUTHOR]

The interface between a screen-printed (Tl0.5Pb0.5)(Sr0.85B0.15)2Ca2Cu3Oy (Tl-1223) superconducting film and an untextured Ag substrate is analyzed by transmission electron microscopy (TEM). Preferential orientation between the Tl-1223 grains and the Ag substrate is found. The (001) plane of TI-1223 grains is parallel to and the [113] plane of Ag is almost parallel to the interface. High-resolution TEM images show that CuO2, planes contact the faceted [113] planes of Ag substrate at the interface. A mechanism for the preferential growth of the Tl-1223 (001) film on untextured Ag substrate is proposed. [ABSTRACT FROM AUTHOR]

We report the fabrication of MgB[sub 2] thick films using a simple screen printing method. The substrates investigated were mono-crystalline Al[sub 2]O[sub 3], LaAlO[sub 3], MgO, ZrO, SrTiO[sub 3], Si as well as steel. The dense, polycrystalline MgB[sub 2] films consisted of crystallites with longest dimensions of about 100 nm. No texturing was observed. The transition temperatures T[sub c(0)] varied between 34 and 36 K with transition widths smaller than 2 K. The critical current densities depended only modestly on the external field. At 6 T critical current densities of 1 × 10[sup 8] A/m² could be measured a 10 K. [ABSTRACT FROM AUTHOR]