BEHAVIOR OF TL(2212)-NORMAL METAL POINT CONTACTS UNDER MICROWAVE IRRADIATION

Current-voltage characteristics and their derivatives of S-c-N point c ontacts formed by Tl2Ba2CaCu2O8-x anvil - niobium needle have been stu died in the temperature range from 4.2 to T-c under microwave irradiat ion of wide frequency range. At frequencies of order 10(10) Hz two typ es of excess current (I-exc) dependence on irradiation power level P w as observed. In one case at temperatures near T/T-c congruent to 0.5 a n excess current oscillates with increasing of P as the square of zero order Bessel function. In another case closer to the critical tempera ture (mainly at T/T-c congruent to congruent to 0.9) the enhancement o f I-exc by the microwave power was revealed. Observed effects demonstr ate complicated dynamics of quasiparticles in Tl-based HST.