Low temperature magnetic phase diagram of the cubic non-Fermi liquid system CeIn_(3-x)Sn_x

TL;DR

This study maps the magnetic phase diagram of CeIn_{3-x}Sn_x, revealing a transition from antiferromagnetic to non-Fermi liquid behavior and identifying critical doping levels where magnetic order disappears.

Contribution

It provides the first detailed phase diagram of a cubic Ce-lattice non-Fermi liquid system with T_N(x) reaching zero, highlighting the evolution of magnetic states with Sn doping.

Findings

Disappearance of antiferromagnetic order near x_c ~ 0.7

Observation of non-Fermi liquid signatures between x=0.4 and 0.7

First order phase transition within 0.25 < x < 0.5

Abstract

In this paper we report a comprehensive study of the magnetic susceptibility (\chi), resistivity (\rho), and specific heat (C_P), down to 0.5 K of the cubic CeIn_(3-x)Sn_x alloy. The ground state of this system evolves from antiferromagnetic (AF) in CeIn_3(T_N=10.2 K) to intermediate-valent in CeSn_3, and represents the first example of a Ce-lattice cubic non-Fermi liquid (NFL) system where T_N(x) can be traced down to T=0 over more than a decade of temperature. Our results indicate that the disappearance of the AF state occurs near x_c ~ 0.7, although already at x ~ 0.4 significant modifications of the magnetic ground state are observed. Between these concentrations, clear NFL signatures are observed, such as \rho(T)\approx \rho_0 + A T^n (with n<1.5) and C_P(T)\propto -T ln(T) dependencies. Within the ordered phase a first order phase transition occurs for 0.25 < x < 0.5. With larger Sn doping, different weak \rho(T) dependencies are observed at low temperatures between x=1 and x=3 while C_P/T shows only a weak temperature dependence.