Magnetic Behavior in RRhX (R = rare earths; X=B, C) Compounds

TL;DR

This paper investigates the magnetic properties of RRhX (X=B,C) compounds with various rare earth elements, revealing diverse magnetic behaviors, crystal field effects, and unique electrical resistivity features linked to their structure and composition.

Contribution

It provides a comprehensive analysis of magnetic and electrical properties of RRhX compounds, highlighting new insights into their magnetic ordering and electronic behavior based on rare earth variation.

Findings

Most compounds exhibit ferromagnetic ordering at low temperatures.

Pr compounds show significant crystal field effects with nonmagnetic ground states.

GdRhB's resistivity behavior suggests short-range spin fluctuations.

Abstract

We report on the magnetic behavior of RRhB (R = La, Ce, Pr, Nd, Gd, Tb and Tm) and RRhC (R = La, Ce, Pr and Gd) compounds crystallizing in the cubic perovskite type structure with space group Pm3m. The heat capacity data on Pauli-paramagnetic LaRhB and LaRhC indicate a high frequency vibrating motion of boron and carbon atoms in the unit cell. Ce is in -like nonmagnetic state in both the compounds. Pr compounds show a dominant crystal field effect with a nonmagnetic singlet ground state in PrRhB and a nonmagnetic quadrupolar doublet in PrRhC. Compounds with other rare earths order ferromagnetically at low temperatures except TmRhB in which the zero field evolution of magnetic interactions is relatively more complicated. The electrical resistivity of GdRhB decreases with increasing temperature in the paramagnetic state in the vicinity of T, which is rarely seen in ferromagnets. The behavior is discussed to be arising due to the short range spin fluctuation and a possible contribution from Fermi surface geometry.