Complex Magnetic Phase Diagram Near the Quantum Critical Point in CeIn3-xSnx

P. PEDRAZZINI; M. GÓMEZ BERISSO; J. G. SERENI; N. CAROCA-CANALES; M. DEPPE; C. GEIBEL

ACTA PHYSICA POLONICA B

THE POLISH PHYSICAL SOCIETY

Lugar: Cracovia; Año: 2003 vol. 34 p. 363 - 366

0587-4254

A recent reinvestigation of the alloy system CeIn3-xSnx between the antiferromagnetic (AF) Kondo-lattice CeIn3 and the intermediate valent CeSn3 has shown that the AF order disappears at a quantum critical point (QCP) at xcapprox 0.65. Preliminary evidences for a first order transition below TN at xc, indicating a complex magnetic phase diagram, have motivated the present detailed investigation of specific heat and resistivity on fine tuned samples in the 0.25 leq x leq xc range. These results confirm the first order transition at TI < TN in a reduced concentration range (0.25 < x < 0.47) and suggest that the phase boundary TI(x) merge with the TN(x) near xapprox 0.37, leading to a tetracritical point. A similar first order transition was previously observed in the CeCu2(Si,Ge)2 system at low Ge-concentration. Since in this alloy the first order transition also appears in the vicinity of a QCP, the question arises concerning how general this property is at AF critical points in Ce-based alloy systems.