Properties of MgB_2/In composite thick films on ceramic substrates prepared by a screen printing method

摘要

In-free and In-added MgB_2 thick films were prepared on ceramic substrates (MgO, YSZ, SrTiO_3 and A1_2O_3) using a simple screen printing method. For In-free films, the adhesion between the films and the substrates were very weak; about 10-40 percent of these films peeled off after firing. We examined the temperature dependence of the resistivity using the non-separated films. These films showed metallic behavior from room temperature to T_(c(onset))= 39.7 K and attained zero resistivity at T_(c(end point)) = 34.0-37.7 K, depending on the kinds of substrate. For In-added films formed on MgO, almost all films adhere well to the substrates and the transport J_c (4.2 K, 0 T) were also improved remarkably; 70 A cm~(-2) for In-free film and 1.6 X 10~3 A cm~(-2) for 18 vol. percent In film.