Novel relation between T-c and low-T energy gap 2 Delta(o) in Bi2212 and La214: an STS study

On the basis of electronic specific heat, magnetic susceptibility and STS d ata in La214, we report that a pseudogap of almost the same scale as the lo w-T (T<<T-c) gap Delta (o) will develop below T*similar toT(co)=2 Delta (o) /4.3k(B) in La214 as in Bi2212. We also report that over a wide hole doping p range in both systems, T-c almost scales with p Delta (o), and suggest t hat similar top Delta (o) will function as an effective energy gap in deter mining T-c.