Interplay between 3d and 4f magnetism in CeCoPO

TL;DR

This study investigates the magnetic properties of CeCoPO, revealing ferromagnetic ordering of Co-3d electrons and proximity to Ce-ion magnetism, with implications for understanding high-temperature superconductor analogs.

Contribution

It provides detailed experimental insights into the interplay between 3d and 4f magnetism in CeCoPO, a compound related to high-temperature superconductors.

Findings

Ferromagnetic ordering below 75K of Co-3d electrons.

Ce-ions are near magnetic instability with a Kondo temperature of ~40K.

Enhanced Sommerfeld coefficient indicating heavy fermion behavior.

Abstract

The ground state properties of CeCoPO, a homologue of the new high temperature superconductors RFePnO1-xFx, were studied by means of susceptibility, specific heat, and resistivity measurements on polycrystals. The observation of a well defined Curie-Weiss behavior above 230K with mu_eff=2.9mu_B and a ferromagnetic ordering below T_C=75K is similar to what was observed in LaCoPO and points to magnetism of the Co-3d electrons. However, the Ce-ions are on the border to magnetism with a Kondo scale of T_K~40K and show an enhanced Sommerfeld-coefficient of \gamma~200mJ/molK^2.