Europium nitride: A novel diluted magnetic semiconductor

TL;DR

Europium nitride is identified as a new diluted magnetic semiconductor exhibiting ferromagnetism at 120 K due to mixed Eu charge states, with transport measurements providing insights into its exchange mechanisms.

Contribution

This study demonstrates that EuN with 15-20% Eu in the 2+ state is ferromagnetic, establishing EuN as a novel diluted magnetic semiconductor.

Findings

EuN exhibits ferromagnetism at up to 120 K.

Ferromagnetism is intrinsic to EuN with mixed Eu charge states.

Transport measurements suggest specific exchange mechanisms.

Abstract

Europium nitride is semiconducting and contains non-magnetic \3+, but sub-stoichiometric EuN has Eu in a mix of 2+ and 3+ charge states. We show that at \2+ ~concentrations near 15-20% EuN is ferromagnetic with a Curie temperature as high as 120 K. The \3+ ~polarization follows that of the \2+, confirming that the ferromagnetism is intrinsic to the EuN which is thus a novel diluted magnetic semiconductor. Transport measurements shed light on the likely exchange mechanisms.