CeRu2Si2: an example of heavy fermion metamagnetism

Fermi Surface Properties, Metamagnetic Transition and Quantum Phase Transition of CeRu2Si2 and Its Alloys Probed by the dHvA Effect

“…It is reported that the lower part and the upper part of the enclosed area by the broken line are connected at lowest temperatures. 73,76,77 The shape of the enclosed area is also similar to the area where the resistivity shows the Fermi liquid behavior, although in this case T * is about 0.5 K. 77 The shaded band shows schematically the behavior of the metamagnetic crossover. That is, (1) the metamagnetic transition is very sharp at low temperatures but still has a finite transition width at the lowest temperatures, and (2) the width becomes broader with increasing temperature and the transition behavior becomes obscured at temperatures comparable to T * or T K .…”

“…Figures 14(a), (b) and (c) show schematic phase diagrams of Ce x La 1−x Ru 2 Si 2 as a function of magnetic field and temperature for x > x c , x < x c but x is close to x c , and x < x c , respectively. The broken line denotes crossover line and is drawn schematically from the points where thermal expansion coefficient shows anomaly 73 or C/T becomes maximum. 74,75 The temperature for the end point at zero magnetic field of the crossover line is denoted as T * .…”

Decoupling between Field-Instabilities of Antiferromagnetism and Pseudo-Metamagnetism in Rh-Doped CeRu2Si2Kondo Lattice

“…The effect of the volume change via a tuning parameter δ have been achieved first by pressure or by doping on Ce 1−x La x Ru 2 Si 2 . 3,4) The pure system CeRu 2 Si 2 at P = 0 is already in a PM ground state; the effective critical pressure P c is at a slightly negative pressure of a few kbar. Expanding the volume by La substitution on the Ce side pushes to reenter in the AF domain for x > x c ∼ 0.075; the AF-PM transition at T = 0 K corresponds to a critical volume V c achieved at δ c which is equivalent to P c or x c .…”

Quantum phase transitions

“…A metamagnetic transition occurs in a field of BM « 8 T [169,170], which manifests itself as a steep jump in the magnetization curve M{B). The corresponding maximum in dM/dB at BM = 8 T is much more pronounced and much sharper than in CeCue at BM = 2 T It is interesting to note in the present context that aU the way through the metamagnetic transition, CeRu2Si2 exhibits weU-defined FL behavior as evidenced by the prevalence of de Haas-van Alphen (dHvA) oscfllations very close to the transition [171].…”