Magneto-optical behaviour of EuIn_2P_2

TL;DR

This study investigates the magneto-optical properties of EuIn2P2, revealing magnetic ordering at 24 K, significant magnetoresistance, spectral weight transfer with magnetic field, and insights into charge-carrier dynamics related to hybridization effects.

Contribution

It provides the first detailed magneto-optical analysis of EuIn2P2, linking spectral weight transfer and Drude weight enhancement to magnetic and electronic properties.

Findings

Magnetic ordering at 24 K with large magnetoresistance

Spectral weight transfer from high energies to low-energy metallic and mid-infrared signals

Increase in Drude weight correlating with magnetization and charge-carrier concentration

Abstract

We report results of a magneto-optical investigation of the Zintl-phase compound EuIn$_2$P$_2$. The compound orders magnetically at $T_C$=24 K and exhibits concomitant large magnetoresistance effects. For $T\le$50 K and increasing magnetic fields we observe a transfer of spectral weight in $\sigma_1(\omega)$ from energies above 1 eV into the low-energy metallic component as well as into a mid-infrared signal centered at about 600 cm$^{-1}$. This latter absorption is reminiscent to what has been seen in a large variety of so-called Kondo materials and ascribed to excitations across the hybridization gap. The observed gain of Drude weight upon increasing magnetic field suggests an enhancement of the itinerant charge-carrier concentration due to the increasing magnetization, a phenomenon that was previously observed in other compounds which exhibit colossal magnetoresistive effects.