Oxygen vacancies (VOs) effects on magnetic ordering in Eu0.5Ba0.5TiO3-{\delta} (EBTO3-{\delta}) thin films have been investigated using a combination of experimental measurements and first-principles density-functional calculations. Two kinds of EBTO3-{\delta}thin films with different oxygen deficiency have been fabricated. A nuclear resonance backscattering spectrometry technique has been used to quantitatively measure contents of the VOs. Eu0.5Ba0.5TiO3 ceramics have been known to exhibit ferroelectric (FE) and G-type antiferromagnetic (AFM) properties. While, a ferromagnetic (FM) behavior with a Curie temperature of 1.85 K has been found in the EBTO3-{\delta} thin films. Spin-polarized Ti3+ ions, which originated from the VOs, has been proven to mediate a FM coupling between the local Eu 4f spins and were believed to be responsible for the great change of the magnetic ordering. Our work opens up a new avenue for developing FM-FE materials by manipulating the oxygen deficiency in AFM-FE multiferroics.
@article{arxiv.1304.0300,
title = {Oxygen-Vacancy-Induced Antiferromagnetism to Ferromagnetism Transformation in Multiferroic Thin Films},
author = {Weiwei Li and Run Zhao and Le Wang and Rujun Tang and Yuanyuan Zhu and Joo Hwan Lee and Haixia Cao and Tianyi Cai and Haizhong Guo and Can Wang and Langsheng Ling and Li Pi and Kuijuan Jin and Yuheng Zhang and Haiyan Wang and Yongqiang Wang and Sheng Ju and Hao Yang},
journal= {arXiv preprint arXiv:1304.0300},
year = {2013}
}