Observation of de Haas-van Alphen oscillations across the phase diagram of CeRh1-xCoxIn5

The evolution of the Fermi surface of CeRh1-xCoxIn5 was studied as a function of Co concentration x via measurements of the de Haas-van Alphen effect. We observe several quantum oscillation frequencies in single crystal samples prepared with values of x spanning the alloy phase diagram. By tracking the evolution of these frequencies as the applied magnetic field is rotated, we establish that the Fermi surface undergoes an abrupt change in shape when x ≊ 0.4. This is well away from the quantum critical concentration x ≊ 0.8 where antiferromagnetic order gives way to paramagnetism.