High-field magnetization and magnetic phase transition in CeOs2Al10

TL;DR

This study investigates the high-field magnetization and magnetic phase transitions in CeOs2Al10, revealing coexistence of Kondo singlet formation and antiferromagnetic order, and constructing a detailed magnetic phase diagram.

Contribution

It provides new insights into the magnetic behavior of CeOs2Al10 under high magnetic fields, including the coexistence of Kondo singlet and antiferromagnetic phases and the anisotropic suppression of spin degrees of freedom.

Findings

Kondo singlet forms below T_max  40 K

Antiferromagnetic order persists below T_0  29 K

Magnetic phase diagram constructed for H // a

Abstract

We have studied the magnetization of CeOs2Al10 in high magnetic fields up to 55 T for H // a and constructed the magnetic phase diagram for H // a. The magnetization curve shows a concave H dependence below T_max \sim40 K which is higher than the transition temperature T_0 \sim29 K. The magnetic susceptibility along the a-axis shows a smooth and continuous decrease down to \sim20 K below T_max \sim40 K without showing an anomaly at T_0. From these two results, a Kondo singlet is formed below T_max and coexists with the antiferro magnetic order below T_0. We also propose that the larger suppression of the spin degrees of freedom along the a-axis than along the c-axis below T_max is associated with the origin of the antiferro magnetic component.