High-temperature instability and low-temperature magnetism of RTIn compounds, the case of CePtIn

Abstract

Cerium-based intermetallics stay in the foreground of scientific interest for several decades due to their frequently complex properties derived from the competition between long-range interactions and Kondo screening acting on a single 4f electron. The present work is dedicated to the heavy-fermion CePtIn intermetallic compound which was previously concluded to reveal paramagnetic properties and non-Fermi-liquid behaviour down to the lowest temperatures. Our study confirms this behaviour. Considering the previous reports on the physical properties of CePtIn, we focus on its structural and phase stability at high temperatures and crystal-field-related magnetic properties at low temperatures. DSC and powder X-ray diffraction measurements demonstrate initial CePtIn phase degradation and decomposition and formation of binary intermetallics at high temperatures. The inelastic neutron scattering experiment identifies crystal field excitation at 9.8 meV. The second CF excitation, expected for Ce³⁺-based system, is proposed at significantly higher energy. The results are discussed in the framework of CePdIn and LaPtIn analogues.