Universal behavior of $\rm CePd_{1-x}Rh_x$ Ferromagnet at Quantum Critical Point

Shaginyan, V. R.; Popov, K. G.; Artamonov, S. A.

Universal behavior of $\rm CePd_{1-x}Rh_x$ Ferromagnet at Quantum Critical Point

Authors

Shaginyan, V. R.

Popov, K. G.

Artamonov, S. A.

Description

The heavy-fermion metal $\rm CePd_{1-x}Rh_x$ can be tuned from ferromagnetism at $x=0$ to non-magnetic state at some critical concentration $x_c$. The non-Fermi liquid behavior (NFL) at $x\simeq x_c$ is recognized by power low dependence of the specific heat $C(T)$ given by the electronic contribution, magnetic susceptibility $χ(T)$ and volume expansion coefficient $α(T)$ at low temperatures: $C/T\proptoχ(T)\proptoα(T)/T\propto1/\sqrt{T}$. We also demonstrate that the behavior of normalized effective mass $M^*_N$ observed in $\rm CePd_{1-x}Rh_x$ at $x\simeq 0.8$ agrees with that of $M^*_N$ observed in paramagnetic $\rm CeRu_2Si_2$ and conclude that these alloys exhibit the universal NFL thermodynamic behavior at their quantum critical points. We show that the NFL behavior of $\rm CePd_{1-x}Rh_x$ can be accounted for within frameworks of quasiparticle picture and fermion condensation quantum phase transition, while this alloy exhibits a universal thermodynamic NFL behavior which is independent of the characteristic features of the given alloy such as its lattice structure, magnetic ground state, dimension etc.
5 pages, 3 figures