S.Y. Dong

Noise measurement of YBa2Cu3O7−x and Ti2Ba2Ca2Cu3O10−x thin films

The noise of YBa2Cu3O7−x and Tl2Ba2Cr2Cu3O10−x thin films in the frequency range from 0.5 Hz to 100 kHz was studied. In the normal state, it was found that 1/f noise dominated, with a magnitude strongly dependent on temperature. In the superconducting state, the noise was only observable at frequencies below 5 Hz with our present setup. Equilibrium thermal fluctuation noise was not observed in these films.

Structural and electrical properties of YBa2Cu3O7−x films on SrTiO3(110) substrates

The structural and electrical properties of {ital in} {ital situ} laser deposited thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} on SrTiO{sub 3}(110) substrates were studied as a function of deposition temperature. It was found that at low temperatures, grains with the {l angle}110{r angle} axis perpendicular to the substrate surface dominated. At higher temperatures, {l angle}103{r angle} perpendicular films were obtained. The {ital J}{sub {ital c}} was found to be extremely anisotropic. For {l angle}103{r angle} perpendicular films at 70 K, the {ital J}{sub {ital c}}s were found to be 0.85{times}10{sup 6} A/cm{sup 2} and 5{times}10{sup 2} A/cm{sup 2} along the substrate {l angle}100{r angle} and {l angle}110{r angle} directions, respectively.

Speed of optically controlled superconducting devices

The speed of optically controlled superconducting devices is discussed. The results of experimental measurements on the speed of nonequilibrium carrier recombination are reviewed. These results indicate that a voltage change can be induced in YBCO samples by a short laser pulse. It is shown that high-Tc superconducting devices can potentially operate in the subpicosecond regime.

Structural and electrical properties of YBa sub 2 Cu sub 3 O sub 7 minus x films on SrTiO sub 3 (110) substrates

The structural and electrical properties of {ital in} {ital situ} laser deposited thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} on SrTiO{sub 3}(110) substrates were studied as a function of deposition temperature. It was found that at low temperatures, grains with the {l angle}110{r angle} axis perpendicular to the substrate surface dominated. At higher temperatures, {l angle}103{r angle} perpendicular films were obtained. The {ital J}{sub {ital c}} was found to be extremely anisotropic. For {l angle}103{r angle} perpendicular films at 70 K, the {ital J}{sub {ital c}}s were found to be 0.85{times}10{sup 6} A/cm{sup 2} and 5{times}10{sup 2} A/cm{sup 2} along the substrate {l angle}100{r angle} and {l angle}110{r angle} directions, respectively.

Structural and electrical properties of YBa2Cu3O7−xfilms on SrTiO3(110) substrates

The structural and electrical properties of {ital in} {ital situ} laser deposited thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} on SrTiO{sub 3}(110) substrates were studied as a function of deposition temperature. It was found that at low temperatures, grains with the {l angle}110{r angle} axis perpendicular to the substrate surface dominated. At higher temperatures, {l angle}103{r angle} perpendicular films were obtained. The {ital J}{sub {ital c}} was found to be extremely anisotropic. For {l angle}103{r angle} perpendicular films at 70 K, the {ital J}{sub {ital c}}s were found to be 0.85{times}10{sup 6} A/cm{sup 2} and 5{times}10{sup 2} A/cm{sup 2} along the substrate {l angle}100{r angle} and {l angle}110{r angle} directions, respectively.