Electronic structure studies on single crystalline Nd2PdSi3, an exotic Nd-based intermetallic: Evidence for Nd 4f hybridization

TL;DR

This study investigates the electronic structure of Nd2PdSi3, revealing significant Nd 4f hybridization with conduction electrons, which may explain its unusual ferromagnetic order and high magnetic transition temperature.

Contribution

It provides detailed experimental and theoretical insights into Nd 4f hybridization in Nd2PdSi3, a rare case among Nd-based intermetallics, highlighting its impact on magnetic properties.

Findings

Significant Pd 4d-Nd 4f hybridization observed

States near Fermi level dominated by Nd 4f-Si 3p hybridized states

Strong final state effects in Nd 3d core level spectra

Abstract

In the series R2PdSi3, Nd2PdSi3 is an anomalous compound in the sense that it exhibits ferromagnetic order unlike other members in this family. The magnetic ordering temperature is also unusually high compared to the expected value for a Nd-based system, assuming 4f localization. Here, we have studied the electronic structure of single crystalline Nd2PdSi3 employing high resolution photoemission spectroscopy and ab initio band structure calculations. Theoretical results obtained for the effective electron correlation strength of 6 eV corroborate well with the experimental valence band spectra. While there is significant Pd 4d-Nd 4f hybridization, the states near the Fermi level are found to be dominated by hybridized Nd 4f-Si 3p states. Nd 3d core level spectrum exhibits multiple features manifesting strong final state effects due to electron correlation, charge transfer and collective excitations. These results serve as one of the rare demonstrations of hybridization of Nd 4$f$ states with the conduction electrons possibly responsible for the exoticity of this compound.