Quadrupolar interactions in Pr compounds: PrFe4P12 and PrBa2Cu3O6

TL;DR

This paper investigates the role of quadrupolar interactions in Pr-based compounds, specifically PrFe4P12 and PrBa2Cu3O6, highlighting their importance in magnetic ordering phenomena and crystal field level degeneracies.

Contribution

It provides a detailed analysis of crystal field models with near-degenerate levels and demonstrates the significance of quadrupolar interactions in explaining experimental observations.

Findings

Gamma1-Gamma4 level scheme explains antiferroquadrupolar order in PrFe4P12

Quadrupolar interactions are crucial for understanding Pr ordering in PrBa2Cu3O6

Near-degeneracy of crystal field levels influences magnetic properties

Abstract

We examine trivalent Pr crystal field models with near-degeneracy of the two lowest crystal field levels, where interaction-induced quadrupolar and dipolar moments are as important as the permanent moments of the crystal field ground state. We find that the Gamma1-Gamma4 level scheme yields a successful description of the antiferroquadrupolar ordering of PrFe4P12. For PrBa2Cu3O6, we argue that quadrupolar interaction is important for understanding the Pr ordering transition at 11K.