Scaling of the physical properties in Ba(Fe,Ni)2As2 single crystals: Evidence for quantum fluctuations

We report on local magnetization, tunnel diode oscillators, and specific-heat measurements in a series of Ba(NixFe1-x)2As2 single crystals (0.26leqxleq0.74). We show that the London penetration depth lambda(T)=lambda(0)+Deltalambda(T) scales as lambda(0)propto1/Tc0.85$pm$0.2, Deltalambda(T)proptoT2.3$pm$0.3 (for T