  In this paper we review some of our recent experimental and theoretical
results on transport and thermodynamic properties of heavy-fermion alloys
Ce(1-x)Yb(x)CoIn5. Charge transport measurements under magnetic field and
pressure on these single crystalline alloys revealed that: (i) relatively small
Yb substitution suppresses the field induced quantum critical point, with a
complete suppression for nominal Yb doping x>0.20; (ii) the superconducting
transition temperature Tc and Kondo lattice coherence temperature T* decrease
with x, yet they remain finite over the wide range of Yb concentrations; (iii)
both Tc and T* increase with pressure; (iv) there are two contributions to
resistivity, which show different temperature and pressure dependences,
implying that both heavy and light quasiparticles contribute to inelastic
scattering. We also analyzed theoretically the pressure dependence of both T*
and Tc within the composite pairing theory. In the purely static limit, when we
ignore the lattice dynamics, we find that the composite pairing mechanism
necessarily causes opposite behaviors of T* and Tc with pressure: if T* grows
with pressure, Tc must decrease with pressure and vice versa.
