Magnetic order in Pr2Pd3Ge5 and possible heavy fermion behavior in Pr2Rh3Ge5

TL;DR

This study investigates two new praseodymium-based intermetallic compounds, revealing magnetic order in one and possible heavy fermion behavior in the other, through comprehensive magnetic, thermal, and electrical measurements.

Contribution

The paper reports the synthesis and detailed characterization of Pr$_{2}$Pd$_{3}$Ge$_{5}$ and Pr$_{2}$Rh$_{3}$Ge$_{5}$, highlighting magnetic transitions and heavy fermion features, which are novel findings for these compounds.

Findings

Pr$_{2}$Pd$_{3}$Ge$_{5}$ shows two magnetic transitions at 7.5 K and 8.3 K.

Pr$_{2}$Rh$_{3}$Ge$_{5}$ exhibits heavy fermion behavior with a large Sommerfeld coefficient.

Pr$_{2}$Pd$_{3}$Ge$_{5}$ displays field-induced metamagnetic transition and large magnetoresistance.

Abstract

We report our results on two new ternary intermetallic compounds Pr$_{2}$Pd$_{3}$Ge$_{5}$ and Pr$_{2}$Rh$_{3}$Ge$_{5}$ based on magnetic susceptibility, magnetization, specific heat, resistivity and magnetoresistance data. These compounds form in U$_{2}$Co$_{3}$Si$_{5}$-type orthorhombic structure (space group \textit{Ibam}). Pr$_{2}$Pd$_{3}$Ge$_{5}$ exhibits two magnetic transitions at T$_{N1}$ = 7.5 K and T$_{N2}$ = 8.3 K. In the magnetically ordered state Pr$_{2}$Pd$_{3}$Ge$_{5}$ exhibits a field induced metamagnetic transition and unusually large magnetoresistance. Pr$_{2}$Rh$_{3}$Ge$_{5}$ does not show any phase transition down to 0.5 K. It has a CEF singlet ground state, separated from the first excited state by about 10 K. The low lying crystal field excitations lead to exciton mediated electronic mass enhancement as evidenced by large Sommerfeld coefficient ($\gamma$ $\sim$ 80 mJ/mol K$^2$) in Pr$_{2}$Rh$_{3}$Ge$_{5}$.