OBSERVATION OF THE 2-CHANNEL QUADRUPOLAR KONDO EFFECT IN Y1-XUXPD3

We present measurements of electrical resistivity rho(T), magnetic susceptibility chi(T), and specific heat C(T) for the system Y1-xUxPd3. The data are consistent with nearly localized tetravalent uranium ions leading to "Fermi-level tuning" and competition between single ion Kondo (0 < x less-than-or-equal-to 0.2) and cooperative spin glass-like (0.3 less-than-or-equal-to x less-than-or-equal-to 0.5) behavior. The Kondo behavior is unusual and well described by the two-channel quadrupolar Kondo effect. At low temperatures T << T(K), where T(K) is the Kondo temperature, the electrical resistivity varies nearly linearly with temperature rho(T)/rho(0) almost-equal-to 1 - T/(aT(K)), and the electronic specific heat diverges logarithmically DELTA-C/T almost-equal-to -(1/T(K))lnT with a finite residual T = 0 entropy S(0) almost-equal-to (R/2)ln2. This appears to be the first example of the quadrupolar Kondo effect and two-channel behavior in a dilute alloy and the first example of "marginal Fermi liquid" phenomenology in a fully three-dimensional system.