Growth and characterization of 2 inch double-sided Tl₂Ba₂CaCu₂O₈thin films on LaAlO₃substrates

Abstract

Superconducting Tl2Ba2CaCu2O8 thin films (Tl-2212) have been reproducibly fabricated on both sides of 2 inch LaAlO3(001) substrates by using a so-called two-step process. A simple and flexible horizontal arrangement inside the crucible during thallination has been proposed, to ensure a good convection of thallous oxide vapor around the film surface, and thus a high film quality on both sides. A good uniformity over the whole area of the films has been realized. The films are strongly textured, with the c-axis perpendicular to the substrate surface, and they show the fourfold symmetry of the tetragonal crystal structure. The full width at half maximum of the (002) peak for both films on the best sample is 0.43° and 0.55° respectively. The films exhibit flat terraces with particles and shallow holes, but free of microcracks. The superconducting critical temperatures fall in the range 105–108.5 K. The critical current densities are between 1.0 × 106 and 4.8 × 106 A cm−2 at 77 K. The microwave surface resistances at the central area of the films are around 500 μΩ at 77 K and 10 GHz. These films are suitable for microwave applications.

Effect of Carbon Nanotube Addition on the Superconducting Properties of BSCCO Samples Textured via Laser Floating Zone Technique

“…These works have used different approaches, as doping [10][11][12][13][14][15], which leads to important changes in charge carrier concentration and also release the restriction of spin alignment due to the spin lattice interaction [16]. Besides chemical doping, grain alignment has also widely used the different production techniques to obtain high quality and homogeneous samples [17][18][19][20][21][22]. When BSCCO materials are properly textured, their transport properties are improved significantly compared with the nontextured materials [23][24][25].…”

The Growth of (00l)-Oriented CeO₂ Buffer Layers on R-Cut Sapphire Substrates for the Epitaxy of Tl-2212 Superconducting Films

“…High temperature superconducting (HTS) thin film is a kind of important material used in superconducting electronics applications, including high-frequency electronic devices and Josephson junction devices [1]. In the practical HTS thin films, Tl 2 Ba 2 CaCu 2 O 8 (Tl-2212) films are getting more and more attention on passive microwave devices due to their high critical temperature [2][3][4], high critical current density, low microwave surface resistance and strong anti-humidity [5][6][7][8].…”

Fabrication of double-sided Tl2Ba2CaCu2O8superconducting thin films on large-area sapphire substrates

“…Since the high temperature superconductors (HTSs) were discovered in 1986 [1], many studies have been made on the preparation of epitaxial HTS films because of their increasing application in many areas. One of the major applications of HTS thin films is in microwave devices [2][3][4][5][6] due to their much lower microwave surface resistance (R s ) than that of normal material and their high microwave power handling capability [7,8].…”