Preparation of Y-Ba-Cu-O thin films by laser evaporation with near-infrared radiation

Abstract

Abstract.We report preparation of Y-Ba-Cu-0 thin films by laser evaporation with near-infrared radiation. Pulsed radiation of a Nd-YAG laser (wavelength 1.06 pm) was used for evaporation of material from the surface of a YBa,Cu,O, ceramic sample. Thin films, deposited on A1203 single-crystal substrates, became conductive after a heat treatment in oxygen atmosphere. One of our films, with a room-temperature resistivity of 1 mQ cm, showed onset of superconductivity at 100 K and had T, values of 94-76 K (90%-10%) for the resistive transition. The films were characterised by RES analysis, SEM and x-ray diffraction.

Superconducting Tl Ca Ba Cu O thin films prepared by diffusion of Tl into an excimer laser ablated Ca 2 Ba 2 Cu 3 O x film

“…3b) consists of an irregular arrangement of grains with different sizes. Similar observations were also made for surfaces of films of the Y-Ba-Cu-O compound obtained by Nd:YAG laser ablation [7,8].…”

“…We have recently developed a technique [6] where thallium was brought into the film by a diffusion technique, too; a Nd:YAG laser was used for preparation of the Ca-Ba-Cu-O film. In the work described here we have used an excimer laser, thus reaching a largely improved film quality.The film deposition system [7] consisted of a vacuum chamber with a base pressure of 5 x 10 -8 Torr. The excimer laser beam (308 nm, pulse duration 40 ns, pulse energy 450 m J) was directed by a quartz optic into the vacuum chamber and focused onto a rotating Ca2Ba2CuaOx sintered bulk target.…”

“…The film deposition system [7] consisted of a vacuum chamber with a base pressure of 5 x 10 -8 Torr. The excimer laser beam (308 nm, pulse duration 40 ns, pulse energy 450 m J) was directed by a quartz optic into the vacuum chamber and focused onto a rotating Ca2Ba2CuaOx sintered bulk target.…”

Preparation of Tl-Ba-Ca-Cu-O thin films by diffusion of Tl into laser evaporated Ba2Ca2Cu3Ox films

“…Material from the target evaporated perpendicular to the target surface. Our arrangement is described in more detail elsewhere [7]. In the next preparation step the film and a T12Ba2Ca2CU3Olo bulk sample were placed in a small stainless steel box (3x2x2cm3); a stainless steel ring (diameter: 10mm, thickness: l mm) served as a spacer between film and bulk sample.…”