Magnetic interactions in a proposed diluted magnetic semiconductor (Ba$_\text{1-x}$K$_\text{x}$)(Zn$_\text{1-y}$Mn$_\text{y}$)$_\text{2}$P$_\text{2}$

TL;DR

This study uses first-principles calculations to explore magnetic interactions in a proposed BaZn2P2-based diluted magnetic semiconductor, revealing how doping and pressure influence ferromagnetism and magnetic coupling.

Contribution

It demonstrates the role of hole carriers and pressure in tuning magnetic interactions in BaZn2P2-based DMS, offering insights for material optimization.

Findings

K doping introduces hole carriers linking Mn moments via p-d hybridization.

Pressure initially enhances, then reduces ferromagnetic coupling around 15 GPa.

Antiferromagnetic coupling between nearest Mn pairs hinders DMS performance.

Abstract

By using first-principles electronic structure calculations, we have studied the magnetic interactions in a proposed BaZn$_2$P$_2$-based diluted magnetic semiconductor (DMS). For a typical compound Ba(Zn$_{0.944}$Mn$_{0.056}$)$_2$P$_2$ with only spin doping, due to the superexchange interaction between Mn atoms and the lack of itinerant carriers, the short-range antiferromagnetic coupling dominates. Partially substituting K atoms for Ba atoms, which introduces itinerant hole carriers into the $p$ orbitals of P atoms so as to link distant Mn moments with the spin-polarized hole carriers via the $p$-$d$ hybridization between P and Mn atoms, is very crucial for the appearance of ferromagnetism in the compound. Furthermore, applying hydrostatic pressure first enhances and then decreases the ferromagnetic coupling in (Ba$_{0.75}$K$_{0.25}$)(Zn$_{0.944}$Mn$_{0.056}$)$_2$P$_2$ at a turning point around 15 GPa, which results from the combined effects of the pressure-induced variations of electron delocalization and $p$-$d$ hybridization. Compared with the BaZn$_2$As$_2$-based DMS, the substitution of P for As can modulate the magnetic coupling effectively. Both the results for BaZn$_2$P$_2$-based and BaZn$_2$As$_2$-based DMSs demonstrate that the robust antiferromagnetic (AFM) coupling between the nearest Mn-Mn pairs bridged by anions is harmful to improving the performance of this II-II-V based DMS materials.