Annealing Effects on Structural and Magnetic Properties of Al doped ZnO Thin Films

Al doped ZnO films have been prepared by dc magnetron sputtering. These films were annealed in different atmosphere and temperature. The crystal structures were analyzed by x-ray diffraction (XRD), and the magnetic properties were measured by a Physical Properties Measurement System (PPMS) with the magnetic field paralleled to the films plane. The results show the microstructure and magnetic properties were influenced by annealing atmosphere. Compared to the films annealed in vacuum, the films annealed in air shows obvious room temperature ferromagnetism, the magnetic moment increases about an order of magnitude. The room temperature ferromagnetism may be associated with a charge transfer between Al and Zn and the variational position of Al in ZnO films in different annealing ambience.

Download Full-text

Improving the Room-Temperature Ferromagnetism in ZnO and Low-Doped ZnO:Ag Films Using GLAD Sputtering

Materials ◽

10.3390/ma14185337 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5337

Author(s):

Marcio A. Correa ◽

Armando Ferreira ◽

Raphael M. Tromer ◽

Leonardo D. Machado ◽

Matheus Gamino ◽

...

Keyword(s):

Magnetic Properties ◽

Room Temperature ◽

Room Temperature Ferromagnetism ◽

Ferromagnetic Metal ◽

Zno Films ◽

Ferromagnetic Behavior ◽

Sensor Element ◽

Promising Candidate ◽

Doped Zno ◽

Metal Doped

ZnO and doped ZnO films with non-ferromagnetic metal have been widely used as biosensor elements. In these studies, the electrochemical measurements are explored, though the electrical impedance of the system. In this sense, the ferromagnetic properties of the material can be used for multifunctionalization of the sensor element using external magnetic fields during the measurements. Within this context, we investigate the room-temperature ferromagnetism in pure ZnO and Ag-doped ZnO films presenting zigzag-like columnar geometry. Specifically, we focus on the films’ structural and quasi-static magnetic properties and disclose that they evolve with the doping of low-Ag concentrations and the columnar geometry employed during the deposition. The magnetic characterization reveals ferromagnetic behavior at room temperature for all studied samples, including the pure ZnO one. By considering computational simulations, we address the origin of ferromagnetism in ZnO and Ag-doped ZnO and interpret our results in terms of the Zn vacancy dynamics, its substitution by an Ag atom in the site, and the influence of the columnar geometry on the magnetic properties of the films. Our findings bring to light an exciting way to induce/explore the room-temperature ferromagnetism of a non-ferromagnetic metal-doped semiconductor as a promising candidate for biosensor applications.

Download Full-text

Effect of defects on room-temperature ferromagnetism of Cr-doped ZnO films

Scripta Materialia ◽

10.1016/j.scriptamat.2008.10.002 ◽

2009 ◽

Vol 60 (4) ◽

pp. 214-217 ◽

Cited By ~ 61

Author(s):

L.J. Zhuge ◽

X.M. Wu ◽

Z.F. Wu ◽

X.M. Chen ◽

Y.D. Meng

Keyword(s):

Room Temperature ◽

Room Temperature Ferromagnetism ◽

Zno Films ◽

Doped Zno

Download Full-text

Room temperature ferromagnetism in Co-doped ZnO films synthesized by magnetron sputtering

High Power Laser and Particle Beams ◽

10.3788/hplpb20152702.24112 ◽

2015 ◽

Vol 27 (2) ◽

pp. 24112

Author(s):

吴兆丰 Wu Zhaofeng ◽

程鲲 Cheng Kun ◽

张峰 Zhang Feng

Keyword(s):

Magnetron Sputtering ◽

Room Temperature ◽

Room Temperature Ferromagnetism ◽

Zno Films ◽

Doped Zno ◽

Co Doped

Download Full-text

Room temperature ferromagnetism and ferroelectricity behavior of (Cu, Li) co-doped ZnO films deposited by reactive magnetron sputtering

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2009.11.044 ◽

2010 ◽

Vol 312 (7) ◽

pp. 906-909 ◽

Cited By ~ 19

Author(s):

C.W. Zou ◽

H.J. Wang ◽

M.L. Yin ◽

M. Li ◽

C.S. Liu ◽

...

Keyword(s):

Magnetron Sputtering ◽

Room Temperature ◽

Room Temperature Ferromagnetism ◽

Reactive Magnetron Sputtering ◽

Zno Films ◽

Reactive Magnetron ◽

Doped Zno ◽

Co Doped

Download Full-text

Ferromagnetic and Optical Properties of Partially Cu-Doped ZnO Films

Zeitschrift für Naturforschung A ◽

10.1515/zna-2009-1114 ◽

2009 ◽

Vol 64 (11) ◽

pp. 765-768 ◽

Cited By ~ 2

Author(s):

Fan-Yong Ran ◽

Masaki Tanemura ◽

Yasuhiko Hayashi ◽

Norihiro Ide ◽

Masao Imaoka ◽

...

Keyword(s):

Optical Properties ◽

Room Temperature ◽

Ion Irradiation ◽

Ion Beam ◽

Room Temperature Ferromagnetism ◽

Intrinsic Property ◽

Zno Films ◽

Cu Doping ◽

Partial Area ◽

Doped Zno

Wurtzite structure ZnO films (3×3 mm2) with a partial-area Cu doping were successfully prepared using a micro-area Ar+-ion beam (~ 380 μm in diameter) and a simultaneous Cu supply at room temperature. A Cu2O phase was formed in the ZnO films by Cu doping. The partially Cu-doped ZnO films exhibited room-temperature ferromagnetism (RTFM) with a saturation magnetization of 1.6×10−5 emu and a coercive field of 40 Oe. Since Zn, Cu, and their compounds are not ferromagnetic, the observed RTFMis attributed to the intrinsic property of Cu-doped ZnO films. As confirmed by the low temperature photoluminescence (PL) spectra, no serious optical damage was recognized in the region without Ar+-ion irradiation. Thus, it was believed that the micro-area Ar+-ion irradiation with a simultaneous Cu supply was promising to integrate the magnetic and optical properties of ZnO-based materials.

Download Full-text