EVIDENCE OF THE SPIN GAP IN HG0.9TL0.1BA2CA2CU3O8+DELTA

We have measured the resistivity rho(T) in high quality Hg0.9Tl0.1Ba2C a2Cu3O8+delta thin films and specific heat in Hg0.9Tl0.1Ba2Ca2Cu3O8+de lta polycrystals samples. The resistivities rho(ab)(T) in the thin fil m samples show systematic deviation from T-linear behavior below a tem perature T-D well above T-c. The magnitude of the specific heat jump d elta gamma(T-c) decreases sharply with little change ill T-c or in gam ma(T) well below or well above T-c. Those behaviors reflect the openin g of the spin gap.