Origin and control of room temperature ferromagnetism in Co,Zn-doped SnO2: oxygen vacancies and their local environment

2020 ◽  
Vol 8 (14) ◽  
pp. 4902-4908 ◽  
Author(s):  
Josha Ho ◽  
Tristan de Boer ◽  
Patrick M. Braun ◽  
Brett Leedahl ◽  
Dhamodaran Manikandan ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Diluted Magnetic Semiconductor ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Semiconductor ◽  
Local Environment ◽  
X Ray ◽  
Local Environments ◽  
Semiconductor System ◽  
Diluted Magnetic ◽  
And Control

The local environments of Co and Zn dopants in SnO2, a diluted magnetic semiconductor system, are studied using X-ray spectroscopy and crystal field calculations, yielding evidence that the ferromagnetism is mediated by oxygen vacancies.

An Electronic Structure Study of Mn Doped ZnO Diluted Magnetic Semiconductor Using X-Ray Absorption and Photoemission Techniques

2009 ◽  
Vol 155 ◽  
pp. 163-172
Author(s):  
R.K. Singhal ◽  
M.S. Dhawan ◽  
S.K. Gaur ◽  
Elisa Saitovitch
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Diluted Magnetic Semiconductor ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Semiconductor ◽  
Transition Metal Ions ◽  
X Ray ◽  
Two Samples ◽  
Diluted Magnetic ◽  
X Ray Absorption

ZnO semiconductor doped with a few per cent of some transition metal ions can exhibit above room temperature ferromagnetism, transforming it into a very promising candidate for future spin-electronic applications. In the present article we have compared the electronic structure of two polycrystalline ZnMnO pellets doped with diluted Mn concentration (2% and 4%), carefully characterized by SQUID and XRD, including Rietveld refinement. The characterization measurements established that the samples have the ZnO lattice with ZnS type Wurtzite hexagonal symmetry and no detectable impurities. The samples exhibit distinctly different magnetic properties. The 2% sample displayed a clear FM ordering at 300 K while the 4% sample did not show any ordering down to 5K. The electronic structure of these two samples has been investigated using Mn L23 x-ray absorption spectroscopy, Zn 2p and 3p, Mn 3p and O 1s x-ray photoemission spectroscopy. Our aim was to find out how the changes in the electronic structure can correlate to the observed magnetic properties in such diluted magnetic semiconductor materials. The results show that most of the Mn ions of the ferromagnetic sample are in the divalent state. For the higher Mn percent nonmagnetic sample, a larger contribution of higher oxidation Mn states are dominant and the oxygen content also increases. The two factors can be correlated to the suppressed ferromagnetism, though it is hard to pinpoint that which of these two weighs more in the suppression mechanism.

Correlation of Surface Morphologies with Mn Compositions of Ga1-xMnxAs Epilayers Grown by Liquid Phase Epitaxy

2002 ◽  
Vol 719 ◽  
Author(s):  
Hwa-Mok Kim ◽  
Jae-Hyeon Leem ◽  
Sung Woo Choi ◽  
Deuk Young Kim ◽  
Tae-Won Kang
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Mixed Solvent ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Energy Dispersive ◽  
Surface Layers ◽  
X Ray ◽  
Diluted Magnetic ◽  
Surface Morphologies

AbstractIn this letter, we investigated the correlation between as-grown surface morphologies and Mn compositions of Ga1-xMnxAs epilayers - a III-V diluted magnetic semiconductor - grown by liquid phase epitaxy (LPE). Ga1-xMnxAs epilayers were grown at 595 °C from 50 % Ga + 50 % Bi mixed solvent. The grown layers were characterized by energy dispersive x-ray analysis (EDS) and atomic forced microscopy (AFM). The Mn composition measured by EDS after growth process was varied from 1 to 7 %. As increasing Mn composition surface morphologies of as-grown Ga1-xMnxAs epilayers were varied. At higher Mn compositions, the morphology of the surface layers degrades strongly, preventing removal of the solution-melt from it. Key words: LPE, as-grown, surface morphology, Mn composition, Ga1-xMnxAs, energy-dispersive x-ray analysis (EDS), atomic forced microscopy (AFM).

Room temperature ferromagnetism of Fe-doped ZnO and MgO thin films prepared by ink-jet printing

2012 ◽  
Vol 1394 ◽  
Author(s):  
Mei Fang ◽  
Wolfgang Voit ◽  
Adrica Kyndiah ◽  
Yan Wu ◽  
Lyubov Belova ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Diluted Magnetic Semiconductor ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Semiconductor ◽  
Ink Jet ◽  
Jet Printing ◽  
Doped Zno ◽  
Diluted Magnetic ◽  
Magnetic Insulator

ABSTRACTRoom temperature magnetic properties of un-doped, as well as 10 at.% Fe-doped ZnO and MgO single-pass layer of ink-jet printed thin films have been investigated to obtain insight into the role of the band gaps and mechanisms for the origin of ferromagnetic order in these materials. It is found that on doping with Fe, the saturation magnetization is enhanced by several-fold in both systems when compared with the respective un-doped thin films. For a “28 nm thick film of Fe-doped ZnO (Diluted Magnetic Semiconductor, DMS) we observe an enhanced moment of 0.465μB /Fe atom while it is around 0.111μB/Fe atom for the doped MgO (Diluted Magnetic Insulator, DMI) film of comparable thickness. Also, the pure ZnO is far more ferromagnetic than pure MgO at comparable low film thicknesses which can be attributed to defect induced magnetism originating from cat-ion vacancies. However, the film thickness dependence of the magnetization and the defect concentrations are found to be significantly different in the two systems so that a comparison of the magnetism becomes more complex for thicker films.

Room Temperature Ferromagnetism in Novel Diluted Magnetic Semiconductor Cd1-xMnxGeP2

2000 ◽  
Vol 39 (Part 2, No. 10A) ◽  
pp. L949-L951 ◽  
Author(s):  
Gennadiy A. Medvedkin ◽  
Takayuki Ishibashi ◽  
Takao Nishi ◽  
Koji Hayata ◽  
Yoichi Hasegawa ◽  
...  
Keyword(s):  
Room Temperature ◽  
Diluted Magnetic Semiconductor ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Semiconductor ◽  
Diluted Magnetic
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