Local Spin Disorder in the Magnetic Kondo Compounds CeNi_1-xCu_x

Abstract

We investigate the cosmological evolution of an interacting phantom energy model in which the phantom field interacts with the dark matter. We discuss the existence and stability of scaling solutions for two types of specific interactions. One is motivated by the conformal transformation in string theory and the other is motivated by analogy with dissipation. In the former case, there exist no scaling solutions. In the latter case, there exist stable scaling solutions, which may give a phenomenological solution of the coincidence problem. Furthermore, the universe either accelerates forever or ends with a singularity, which is determined by not only the model parameters but also the initial velocity of the phantom field.

μSR study of short-range magnetic order in the paramagnetic regime of ErCo2

“…In these examples, the different spin dynamics (namely multiple spin fluctuation rates) detected by the analysis of the μSR spectra are a signature of heterogeneous magnetic phases, including ordered clusters within the paramagnetic regime. 29 In the same way, our results on μSR spectroscopy give insight on the nature of the unusual paramagnetic state of ErCo 2 .…”

“…The fact that muon is a microscopic probe of the magnetism on the sample which needs no large coherence length is relevant for the aim of the present study since it is very sensitive to short-range and other forms of disordered magnetism (cluster-glass, spin-glass). 29,30 A detailed description of muon spin relaxation spectroscopy can be found in Refs. 28, 31, 32, and 33.…”

Theory of the Kondo lattice: competition between Kondo effect and magnetic order

“…Thus, a SG-Kondo transition has been observed experimentally with increasing concentration in disordered alloys around the QCP. Recent experiments performed in CeNi 1 À x Cu x alloys have shown that the phase diagram of these alloys is more complicated [51,52]. In fact, when temperature decreases, for alloys with 0.7 > x > 0.1, there appears a ''cluster spin glass'' phase presenting magnetic inhomogeneities, rather than a classical SG phase.…”

Theory of the Kondo Lattice: Competition Between Kondo Effect and Magnetic Order

“…[53]. However, the experimental situation appears to be really complicate, as shown for example by recent experiments on CeN i 1−x Cu x alloys [51,52]. Thus, further experimental work is certainly necessary, but however the models presented here can account roughly for the behavior of heavy fermion disordered alloys, especially in the vicinity of the quantum critical point.…”

“…This is the case of the magnetic phase diagram of CeN i 1−x Cu x alloys that has been extensively studied [46,47] have shown that the phase diagram of these alloys is more complicate [51,52].…”