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We present measurements of the microwave resistivity at 48 GHz in YBa[sub 2]Cu[sub 3] O[sub 7]-δ film, as a function of the temperature and the magnetic field. The magneto-dissipation from 60 K up to a few kelvins below T[sub c] finds a quantitative description in terms of free flux flow. Approaching T[sub c], the data are not consistent with a dissipative mechanism based solely on flux dynamic. Fluxon viscosity is measured as a function of the temperature, and the in-plane coherence length is estimated. The analysis of the zero-field transition at 48 GHz in terms of anisotropic renormalized fluctuations yields identical estimate. [ABSTRACT FROM AUTHOR]

Describes a cryostatic setup to perform photothermal deflection measurements from room temperature. Use of gaseous nitrogen as a medium where the photodeflection is produced; Sample application to high-temperature superconductors and yttrium-iron garnets.

Interferometric thermal diffusivity measurements and elastic constants obtained by ultrasonic techniques on YFeAlO (with ϰ 4 0, 0.4, 0.8, 1.1) ceramic samples are presented and discussed. The phonon mean free path is given as a function of ϰ using the Boltzmann transport equation. [ABSTRACT FROM AUTHOR]

Samarium element has been substituted to yttrium in Y123 superconducting melt textured bulk samples in order to make the whole fabrication process much faster. A preliminary comparison between directionally solidified YBaCuO and SmBaCuO bulk bars fabricated with the horizontal Bridgman method has been done. The different microstructural and superconducting features are studied by means of X-ray, SEM analysis, ac and dc susceptibility measurements. The quality of Sm123 samples appears comparable with the Y123 one grown using an almost two orders of magnitude lower pulling rate. [ABSTRACT FROM AUTHOR]

Superconducting films of YBaCuO were deposited in situ on LaAlO substrates using single-target 90° off-axis sputtering. The obtained films have tipical T values of 91K. Surface resistance measurements on as-grown films reach 1.1 mΩ at 77K and 10GHz; whilst on ion-etched patterned resonant lines R (77K, 10GHz) it is about 10mΩ. [ABSTRACT FROM AUTHOR]

Rare Earth (Nd,Sm) elements, having relatively large ionic radius, have been substituted for Yttrium in Y123 superconducting melt textured bulk samples. In (Nd,Sm)123 a wider solidification range and higher recrystallization rate than Y123 significantly increase the solidification rate, making the whole process much faster. A preliminary comparison among directionally solidified (Y,Sm,Nd)/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/ bulk bars fabricated by the Horizontal Bridgman method has been done. The different microstructural and superconducting features are studied by X-ray, SEM analysis, and ac and dc magnetic measurements. The (Nd,Sm)123 samples, appear comparable to Y123 grown with a pulling rate almost two orders of magnitude lower. [ABSTRACT FROM PUBLISHER]