DEGRADATION OF YBA2CU3O7-DELTA THICK-FILMS PREPARED ON Y2BACUO5 SUBSTRATES BY THE PAINT-ON METHOD AND ITS USE IN FORMING ONE-HOLE RF-SQUIDS

Is shown, that the degradation process of YBa2Cu3O7-delta thick films, prepared by painting the mixture of (3BaCuO(2) + 2CuO) on Y2BaCuO5 su bstrates, in aqueous environment is layer by layer. The use of this de gradation process in forming microbridges for making one-hole thick-fi lm RF-SQUIDs has been studied. For the first time, such SQUIDs have be en fabricated, they have a noise spectral density S-phi = 2 x 10(-4) P hi(0)/root Hz, an energy resolution epsilon approximate to 2.9 x 10(-2 7) J/Hz and the excessive 1/f noise appears in the frequency region be low 1 Hz.