Interplay of Sm4f and Co3d spins in SmCoAsO

TL;DR

This study investigates the complex magnetic transitions and kinetic arrest phenomena in SmCoAsO, revealing how Sm4f and Co3d spins interact and influence magnetic phase changes with temperature and magnetic field.

Contribution

It provides new experimental evidence of kinetic arrest during FM-AFM transition in SmCoAsO and details the interplay of Sm4f and Co3d spins affecting its magnetic behavior.

Findings

Evidence of kinetic arrest in FM-AFM transition.

Observation of meta-magnetic transitions at specific fields and temperatures.

Magnetization and magneto-transport data supporting complex spin interactions.

Abstract

We present detailed magnetization and magneto-transport studies on the title compound SmCoAsO. In a recent paper we reported [1] the complex magnetism of this compound. SmCoAsO undergoes successive paramagnetic (PM) - ferro-magnetic (FM) - anti-ferro-magnetic (AFM) transitions with decrease in temperature. This is mainly driven via the c-direction interaction of Sm4f (SmO layer) spins with adjacent (CoAs layer) ordered Co3d spins. In this article we present an evidence of kinetic arrest for FM-AFM transition. The isothermal magnetization (MH) loops for SmCoAsO exhibited the meta-magnetic transitions at 6, 8 and 10K at around 80, 60 and 50kOe fields respectively with characteristic hysteresis shoulders along with the non-zero moment at origin, thus suggesting the possibility of kinetic arrest. Suggested kinetic arrest is further evident in zero field-cooled (ZFC) and field-cooled (FC) hysteresis under high fields of up to 140kOe magnetization (MT) and the magneto-transport measurements R(T)H during FM-AFM transition. The time dependent moment experiments exhibited very small (~2-3%) increase of the same below 20kO and decrease for 30kOe at 15K.