Magnetic properties of transition-metal-doped Zn1−xTxO (T=Cr, Mn, Fe, Co, and Ni) thin films with and without intrinsic defects: A density functional study

Authors

Qian Wang, Virginia Commonwealth University, Southwest University
Qiang Sun, Peking University
Puru Jena, Virginia Commonwealth UniversityFollow
Y. Kawazoe, Tohoku University

Document Type

Article

Original Publication Date

2009

Journal/Book/Conference Title

Physical Review B

Volume

79

Issue

11

DOI of Original Publication

10.1103/PhysRevB.79.115407

Comments

Originally published by the American Physical Society at: http://dx.doi.org/10.1103/PhysRevB.79.115407

Date of Submission

April 2015

Abstract

Theoretical calculations based on density-functional theory and generalized gradient approximation have been carried out in studying the electronic structure and magnetic properties of transition-metal-doped Zn1−xTxO (T=Cr, Mn, Fe, Co, and Ni) (112¯0) thin films systematically with and without intrinsic point defects (e.g., vacancies and interstitials), and as function of concentration and distribution of dopants and vacancies. Using large supercells and geometry optimization without symmetry constraint, we are able to determine the sites that metal atoms prefer to occupy, their tendency to cluster, the preferred magnetic coupling between magnetic moments at transition-metal sites, and the effect of intrinsic point defects on the nature of their coupling. Except for Mn atom, which distributes uniformly in ZnO thin films in dilute condition, transition-metal atoms occupying Zn sites prefer to reside on the surface and couple antiferromagnetically. The presence of native point defects has a large effect on the ground-state magnetic structure. In particular, p-type defects such as Zn vacancies play a crucial role in tuning and stabilizing ferromagnetism in Zn1−xTxO thin films (T=Cr, Mn, Fe, and Ni), while n-type defects such as O vacancies or Zn interstitials greatly enhance the ferromagnetic coupling in Zn1−xCoxO thin films. The present study provides a clear insight into the numerous conflicting experimental results on the magnetic properties of T-doped ZnO systems.

Rights

Wang, Q., Sun, Q., Jena, P. Magnetic properties of transition-metal-doped Zn1−xTxO (T=Cr, Mn, Fe, Co, and Ni) thin films with and without intrinsic defects: A density functional study. Physical Review B, 79, 115407 (2009). Copyright © 2014 American Physical Society.

Is Part Of

VCU Physics Publications