Studies on the RF SQUID effect in Tl-Ca-Ba-Cu-O thin films prepared by the spray pyrolysis technique

RF SQUID behaviour in thin films of Tl-Ca-Ba-Cu-O has been studied. The films were prepared by the spray pyrolysis technique. Two films (A and B) which have Tc(R=0) values of 85 K and 103 K respectively, were chosen for the RF SQUID studies. Film A consists mainly of 2122 phase with needle-like grains whereas film B mainly consists of 2223 phase with well connected plate-like grains. RF SQUID modulations in film B were observed up to 101 K. The SQUID was also operated in flux-looked-loop mode. The RF SQUID fabricated from film B was found to exhibit better flux noise performance than that fabricated from film A.