Robust ferromagnetism of single crystalline CoxZn1−xO (0.3 ≤ x ≤ 0.45) epitaxial films with high Co concentration

Authors

Qiang Cao, Shandong University
Dapeng Zhu, Shandong University
Maxiang Fu, Shandong University
Li Cai, Shandong University
Ping Yang, National University of Singapore
Shuang Li, Shenyang National Laboratory for Materials Science
Yinlian Zhu, Shenyang National Laboratory for Materials Science
Xiuliang Ma, Shenyang National Laboratory for Materials Science
Guo-Lei Liu, Shandong University
Yan-Xue Chen, Shandong University
Shi-Shen Yan, Shandong University
Liang-Mo Mei, Shandong University
Xiaolin Wang, University of WollongongFollow

RIS ID

109131

Publication Details

Cao, Q., Zhu, D., Fu, M., Cai, L., Yang, P., Li, S., Zhu, Y., Ma, X., Liu, G., Chen, Y., Yan, S., Mei, L. & Wang, X. (2016). Robust ferromagnetism of single crystalline CoxZn1−xO (0.3 ≤ x ≤ 0.45) epitaxial films with high Co concentration. Applied Physics Letters, 109 (5), 052404-1-052404-5.

Abstract

In contrast to conventional dilute magnetic semiconductors with concentrations of magnetic ions of just a few percent, here, we report the fabrication of epitaxial Cox Zn 1− xO single crystalline films with Co concentrations from x = 0.3 up to 0.45 by radio-frequency oxygen-plasma-assisted molecular beam epitaxy. The films retain their single crystalline wurtzite structure without any other crystallographic phase from precipitates, based on reflection high energy electron diffraction, X-ray diffraction, transmission electron microscopy, and Raman scattering. The results of X-ray diffraction, optical transmission spectroscopy, and in-situ X-ray photoelectron spectroscopy confirm the incorporation of Co2+ cations into the wurtzite lattice. The films exhibit robust ferromagnetism and the magneto-optical Kerr effect at room temperature. The saturation magnetization reaches 265 emu/cm3 at x = 0.45, which corresponds to the average magnetic moment of 1.5 μB per Co atom.