Tuning electromagnetic properties of SrRuO3 epitaxial thin films via atomic control of cation vacancies

Sang A Lee,Jegon Lee,Jong-Seong Bae,Woo Seok Choi,Sung Wng Kim,Sungkyun Park,Suyoun Lee,Seokjae Oh,Won Nam Kang,Jae-Yeol Hwang,Tae Eun Hong,Jiwoong Kim

doi:10.1038/s41598-017-11856-z

Sang A Lee, Jegon Lee + Show 10 more

Open Access

https://doi.org/10.1038/s41598-017-11856-z

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Abstract

Elemental defect in transition metal oxides is an important and intriguing subject that result in modifications in variety of physical properties including atomic and electronic structure, optical and magnetic properties. Understanding the formation of elemental vacancies and their influence on different physical properties is essential in studying the complex oxide thin films. In this study, we investigated the physical properties of epitaxial SrRuO3 thin films by systematically manipulating cation and/or oxygen vacancies, via changing the oxygen partial pressure (P(O2)) during the pulsed laser epitaxy (PLE) growth. Ru vacancies in the low-P(O2)-grown SrRuO3 thin films induce lattice expansion with the suppression of the ferromagnetic TC down to ~120 K. Sr vacancies also disturb the ferromagnetic ordering, even though Sr is not a magnetic element. Our results indicate that both A and B cation vacancies in an ABO3 perovskite can be systematically engineered via PLE, and the structural, electrical, and magnetic properties can be tailored accordingly.

Highlights

Along with the unit cell volume, the Sr/Ru ratio could be systematically modified by controlling P(O2) during the PLE growth
From the stoichiometric condition of P(O2) = 100 mTorr, the lower P(O2) promotes Ru vacancies, which significantly affects the hybridization between the Ru 4d and O 2p orbitals
This results in the increased resistivity and the reduced ferromagnetic ordering of the epitaxial thin film

Summary

Introduction

Heteroepitaxial SRO (001) epitaxial thin films were grown coherently on STO substrates using PLE. Along with the unit cell volume, the Sr/Ru ratio could be systematically modified by controlling P(O2) during the PLE growth. This results in the increased resistivity and the reduced ferromagnetic ordering of the epitaxial thin film. Sr vacancies, induced by growth in the higher P(O2), disturbs the ferromagnetic property Sr is a nonmagnetic element.

Results

Conclusion