Low temperature magnetic properties of Nd2Ru2O7

TL;DR

This study investigates the low-temperature magnetic behavior of Nd2Ru2O7 using various measurements, revealing antiferromagnetic order, Nd3+ moments' long-range order, and an all-in all-out magnetic structure.

Contribution

It provides detailed experimental insights into the magnetic ordering and structure of Nd2Ru2O7 at very low temperatures, including neutron diffraction analysis.

Findings

Antiferromagnetic ordering of Ru4+ moments at 146 K

Long-range order of Nd3+ moments observed below 1.8 K

Magnetic structure determined as all-in all-out

Abstract

We present magnetic susceptibility, heat capacity, and neutron diffraction measurements of polycrystalline Nd2Ru2O7 down to 0.4 K. Three anomalies in the magnetic susceptibility measurements at 146, 21 and 1.8 K are associated with an antiferromagnetic ordering of the Ru4+ moments, a weak ferromagnetic signal attributed to a canting of the Ru4+ and Nd3+ moments, and a long-range-ordering of the Nd3+ moments, respectively. The long-range order of the Nd3+ moments was observed in all the measurements, indicating that the ground state of the compound is not a spin glass. The magnetic entropy of Rln2 accumulated up to 5 K, suggests the Nd3+ has a doublet ground state. Lattice distortions accompany the transitions, as revealed by neutron diffraction measurements, and in agreement with earlier synchrotron x-ray studies. The magnetic moment of the Nd3+ ion at 0.4 K is estimated to be 1.54(2){\mu}B and the magnetic structure is all-in all-out as determined by our neutron diffraction measurements.