Spin canted magnetism, decoupling of charge and spin ordering in NdNiO$_3$

TL;DR

This study investigates the magnetic and charge ordering phenomena in NdNiO$_3$, revealing spin canted antiferromagnetism, non-concurrent charge and spin transitions, and complex magnetic irreversibilities unrelated to spin-glass behavior.

Contribution

It provides detailed insights into the decoupling of charge and spin orderings and the nature of magnetic irreversibilities in NdNiO$_3$, highlighting the first-order charge transition and continuous spin transition.

Findings

Spin canted antiferromagnetic state identified

Charge and spin transitions are not concurrent during cooling

Magnetic irreversibilities are due to anisotropy and domain effects

Abstract

We report detailed magnetization measurements on the perovskite oxide NdNiO$_3$. This system has a first order metal-insulator (M-I) transition at about 200 K which is associated with charge ordering. There is also a concurrent paramagnetic to antiferromagnetic spin ordering transition in the system. We show that the antiferromagnetic state of the nickel sublattice is spin canted. We also show that the concurrency of the charge ordering and spin ordering transitions is seen only while warming up the system from low temperature. The transitions are not concurrent while cooling the system through the M-I transition temperature. This is explained based on the fact that the charge ordering transition is first order while the spin ordering transition is continuous. In the magnetically ordered state the system exhibits ZFC-FC irreversibilities, as well as history-dependent magnetization and aging. Our analysis rules out the possibility of spin-glass or superparamagnetism and suggests that the irreversibilities originate from magnetocrystalline anisotropy and domain wall pinning.