High Field (14Tesla) Magneto Transport of Sm/PrFeAsO

TL;DR

This study investigates high-field magneto-transport properties of SmFeAsO and PrFeAsO, revealing distinct behaviors linked to their electronic states and magnetic interactions, with implications for understanding their ground states.

Contribution

It provides new insights into the magneto-transport behavior of Sm/PrFeAsO at high magnetic fields, highlighting differences in their electronic and magnetic ground states.

Findings

PrFeAsO exhibits almost linear magnetoresistance below 20 K.

SmFeAsO shows nonlinear MR at low fields and no resistivity hump.

PrFeAsO's anomalous behavior is linked to Dirac cone states.

Abstract

We report high field magneto transport of Sm/PrFeAsO. Below spin density wave transition (TSDW), the magneto-resistance (MR) of Sm/PrFeAsO is positive and increasing with decreasing temperature. The MR of SmFeAsO, is found 16%, whereas the same is 21.5% in case of PrFeAsO, at 2.5 K under applied magnetic field of 14 Tesla (T). In case of SmFeAsO, the variation of isothermal MR with field below 20 K is nonlinear at lower magnetic fields (< 2 Tesla) and the same is linear at moderately higher magnetic fields (H \geq 3.5 T). On the other hand PrFeAsO shows almost linear MR at all temperatures below 20 K. The anomalous behavior of MR being exhibited in PrFeAsO is originated from Dirac cone states. The stronger interplay of Fe and Pr ordered moments is responsible for this distinct behavior. PrFeAsO also shows a hump in resistivity (R-T) with possible conduction band (FeAs) mediated ordering of Pr moments at around 12 K. However the same is absent in SmFeAsO even down to 2 K. Our results of high field magneto-transport of up to 14 Tesla brings about clear distinction between ground states of SmFeAsO and PrFeAsO.