The suppression of Curie temperature by Sr doping in diluted ferromagnetic semiconductor (La1-xSrx)(Zn1-yMny)AsO

TL;DR

This study investigates how Sr doping affects the ferromagnetic properties of a layered diluted magnetic semiconductor, revealing that increased Sr levels suppress Curie temperature without structural changes.

Contribution

It demonstrates the suppression of Curie temperature by Sr doping in (La1-xSrx)(Zn1-yMny)AsO, providing insights into carrier doping effects on ferromagnetism in this material.

Findings

Sr doping induces ferromagnetic order below 30 K at 10% doping

Higher Sr levels suppress Curie temperature and saturation moments

No structural transition occurs with Sr doping up to 30%

Abstract

(La1-xSrx)(Zn1-yMny)AsO is a two dimensional diluted ferromagnetic semiconductor that has the advantage of decoupled charge and spin doping. The substitution of Sr2+ for La3+ and Mn2+ for Zn2+ into the parent semiconductor LaZnAsO introduces hole carriers and spins, respectively. This advantage enables us to investigate the influence of carrier doping on the ferromagnetic ordered state through the control of Sr concentrations in (La1-xSrx)(Zn0.9Mn0.1)AsO. 10 % Sr doping results in a ferromagnetic ordering below TC ~ 30 K. Increasing Sr concentration up to 30 % heavily suppresses the Curie temperature and saturation moments. Neutron scattering measurements indicate that no structural transition occurs for (La0.9Sr0.1)(Zn0.9Mn0.1)AsO below 300 K.