Metamagnetic Transition In CeRu2Si2 Research Articles

A possible explanation of meta-magnetic transition in CeRu2Si2 and magnetic behavior in Gd-poor (Ce-Gd)Ru2Si2

Aiming at getting any clue to the mechanism of characteristic behavior of meta-magnetic transition in CeRu2Si2 and the Ce 4f electronic states in Gd-poor contents, the (Ce-Gd)Ru2Si2 crystal mixed system was studied through magnetic measurements. A characteristic behavior of meta-magnetic transition observed in CeRu2Si2 was found to be reproduced in GdRu2Si2 in the temperature range between 30 K and 40 K. The meta-magnetic transition field was increased to higher field by the substitution of small amount of Gd contents of 0.01 and 0.02 at%. Furthermore, the reciprocal susceptibility in CeRu2Si2 (Gd=0) in temperature range between 15 K and 300 K revealed that the electronic state of Ce 4f was dominantly Ce3+, which was in accordance with a previous work, and the electronic states of Ce 4f in CeRu2Si2 could be described by the Van Vleck paramagnetic picture.

Ultrasonic investigation of the heavy fermion compound CeRu2Si2

We have performed ultrasonic measurements on CeRu2Si2 down to 20mK in magnetic fields up to 16T. The longitudinal C11 and C33 exhibit considerable softening of 20% which coincide with ultrasonic absorption around the metamagnetic point HC=7.7T. The transverse C44 and C66 show only a small softening of ≈0.8% around HC. The softening in the longitudinal C11 and C33 comprising a volume strain suggests that the coupling of the order parameter with total symmetry to the volume strain plays a crucial role for the metamagnetic transition in CeRu2Si2.

Characteristic of metamagnetic transition in CeRu2Si2 revealed with hall mobility

Field dependence of the Hall resistivity has been measured below and above a metamagnetic-like transition (MT) at 50 mK-2 K in a high quality single crystal CeRu 2Si2. The MT in the Fermi-liquid region is regarded as a continuous modification of resonance quasi-particle band near the Fermi level and no drastic change of carrier density is observed. In contrast, the MT in the incoherent region exhibits no clear change of effective mass or inelastic scattering time. The strong modification of the MT by the coherent effect is discussed.

Absence of a first-order metamagnetic transition in CeRu2Si2.

Metamagnetic transition of the heavy-electron compound ${\mathrm{CeRu}}_{2}$${\mathrm{Si}}_{2}$ has been examined on high-purity single crystals by means of a static magnetization measurement at very low temperatures down to 90 mK. No hysteresis is observed in the magnetization process. The peak value of the differential susceptibility at the metamagnetic field ${\mathit{B}}_{\mathit{M}}$\ensuremath{\sim}7.7 T follows a simple ${\mathit{T}}^{2}$ law below T\ensuremath{\sim}0.5 K, and saturates to a finite value 1.88${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$/T Ce as T\ensuremath{\rightarrow}0. From these results for two single crystals with slightly different quality, we have confirmed the nonexistence of a first-order phase transition at ${\mathit{B}}_{\mathit{M}}$ in the clean limit of this system. The itinerant nature of the 4f electrons is most likely preserved in the magnetized state at B\ensuremath{\ge}${\mathit{B}}_{\mathit{M}}$.

Change of the Fermi surface at the metamagnetic transition in CeRu2Si2

Abstract From the de Haas-van Alphen experiments in CeRu 2 Si 2 , an itinerant 4f electron-Fermi surface is most likely changed into the localized one at the metamagnetic transition.

Comment on "Phonon effects at the metamagnetic transition in CeRu2Si2"

We reexamine whether or not including lattice effects in a simple model of a Kondo impurity is sufficient to explain observed field effects in metamagnetic CeRu2Si2.Received 19 May 1992DOI:https://doi.org/10.1103/PhysRevB.48.13153©1993 American Physical Society

Electronic states and magnetic correlations in heavy fermion systems studied as two-impurity Kondo problem

Abstract A model is proposed for the metamagnetic transition in CeRu2Si2. Magnetization curve is calculated by taking account of the Kondo volume collapse effect, anfiferromagnetic molecular field and field-dependent effective RKKY interaction deduced from two-impurity calculation. Metamagnetic behavior emerges due to the combination of these three effects, and transition field HM is found to be well scaled with the inverse initial susceptibility 1/ϰ, as observed in experiments.

NMR study of magnetic correlation in CeT 2Si 2 (T = Cu, Ru)

The magnetic properties of a series of CeT2Si2 (T = Cu, Ru) compounds have been studied by 63Cu and 29Si NMR techniques. As for CeCu2Si2 with Tc = 0.72 K, the antiferromagnetic spin correlation appears below around 1 Kin the magnetic field above 5 kOe, suggesting the interrelation between the superconductivity and the antiferromagnetism. At the metamagnetic transition in CeRu2Si2, the low frequency component of spin fluctuation is found to be significantly enhanced.

Phonon effects at the metamagnetic transition in CeRu2Si2.

We present experiments and model calculations concerning the metamagnetic transition in ${\mathrm{CeRu}}_{2}$${\mathrm{Si}}_{2}$. Our sound velocity, sound attenuation (down to 60 mK), and ac magnetic susceptibility measurements (down to 20 mK) all show strong anomalies near the critical magnetic field of this transition. We can account for this behavior using scaling arguments and a more microscopic model based on the Kondo volume collapse.