scholarly journals Physical Investigations of (Co, Mn) Co-Doped ZnO Nanocrystalline Films

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1507
Author(s):  
Bechir Yahmadi ◽  
Olfa Kamoun ◽  
Badriyah Alhalaili ◽  
Safia Alleg ◽  
Ruxandra Vidu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Texture Coefficient ◽  
Room Temperature Ferromagnetism ◽  
Band Gap Energy ◽  
X Ray ◽  
Co Doping ◽  
Glass Substrates ◽  
Doped Zno ◽  
Co Doped

Undoped as well as (Co, Mn) co-doped Zinc oxides have been effectively developed on glass substrates, taking advantage of the spray pyrolysis procedure. The X-ray diffraction XRD as well as X-ray photoelectron spectroscopy (XPS) measurements have recognized a pure hexagonal wurtzite form of ZnO, and no other collateral phases such as MnO2 or CoO2 have been observed as a result of doping. The calculated values of the texture coefficient (TC) were between 0.15 and 5.14, indicating a dominant orientation along the (002) plane. The crystallite size (D) varies with the (Co, Mn) contents. The dislocation density (δ) as well as the residual microstrains increased after Co and Mn doping. Furthermore, the surface morphology of the films has been affected significantly by the Co and Mn incorporation, as shown by the scanning electron microscopy (SEM) investigation. The study of the optical properties exhibits a red shift of the band gap energy (Eg) with the (Co, Mn) co-doping. The magnetic measurements have shown that the undoped and (Co, Mn) co-doped ZnO thin films displayed room-temperature ferromagnetism (RTFM).

Effect of N and P codoping on ZnO properties

2013 ◽  
Vol 645 ◽  
pp. 64-67 ◽  
Author(s):  
Jin Zhong Wang ◽  
Elangovan Elamurugu ◽  
Hong Tao Li ◽  
Shu Jie Jiao ◽  
Lian Cheng Zhao ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Atomic Ratio ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Nitrogen And Phosphorus ◽  
X Ray ◽  
Co Doping ◽  
Glass Substrates ◽  
Doped Zno ◽  
Co Doped

Nitrogen and Phosphorus co-doped (N+P)- zinc oxide (ZnO) films were RF sputtered on corning glass substrates at 350 °C and comparatively studied with undoped, N-, and P- doped ZnO. X-ray diffraction spectra confirmed that the ZnO structure with a preferred orientation along direction. Scanning electron microscope analysis showed different microstructure for the N+P co-doping, and thus probably confirming the co-existence of both the dopants. X-ray photoelectron spectroscopy spectra revealed that the chemical composition in N+P co-doped ZnO are different from that found in undoped, N-, and P- doped ZnO. The atomic ratio of N and P in N+P co-doped ZnO is higher than that in single N or P doped ZnO. One broad ZnO emission peak around 420 nm is observed in photoluminescence spectra. The relative intensity of the strongest peak obtained from co-doped ZnO films is about twice than the P- doped and thrice than the pure and N- doped films.

STRUCTURE AND MAGNETIC PROPERTIES OF Co-DOPED SnO2 NANOWIRES

2011 ◽  
Vol 10 (04n05) ◽  
pp. 967-971 ◽  
Author(s):  
U. K. GOUTAM ◽  
SHASHWATI SEN ◽  
JAGANNATH ◽  
A. K. SINGH ◽  
R. MUKUND ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Ferromagnetic Behavior ◽  
Tubular Furnace ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Sno2 Nanowires ◽  
Tin Metal ◽  
Co Doped

Co -doped SnO2 nanowires were grown by thermal evaporation of a mixture of Tin metal powder and CoCl2 · 6H2O in a tubular furnace. The growth occurs by vapor–solid growth mechanism. Nanowires grew along the sidewall of the alumina boat placed in the tubular furnace and the diameter of these nanowires (as was evident from scanning electron microscopy), was found to be in the range of 50 nm to 200 nm. Co was successfully doped in SnO2 lattice as revealed by X-ray diffraction data and was found to be in Co2+ state in the nanowires as detected by X-ray Photoelectron Spectroscopy measurements. Room temperature magnetic measurements, carried out using Vibrating Sample Magnetometer, indicated ferromagnetic behavior of the nanowires indicating their potential for spintronics applications. With increasing Co doping (upto 1%), the lattice parameters of SnO2 decreased and the saturation magnetization increased, suggesting a strong structure-magnetic property relationship.

The Structural, Electrical, Magnetic Properties of (Cu, Co) Co-Doped ZnO Thin Film

2014 ◽  
Vol 556-562 ◽  
pp. 429-432
Author(s):  
Ping Cao ◽  
Yue Bai ◽  
Zhi Qu
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Sol Gel ◽  
Hall Effect Measurement ◽  
Ferromagnetic Semiconductors ◽  
Zno Thin Film ◽  
Zno Film ◽  
Co Doping ◽  
Doped Zno ◽  
Co Doped

Successful synthesis of room-temperature ferromagnetic semiconductors, (Cu, Co) co-doped ZnO film is obtained by sol-gel method. It is found that the essential ingredient in achieving room-temperature ferromagnetism is Cu co-doping. By Hall-effect measurement ap-type conductivity was observed for the Cu co-doped films, which induced the room-temperature ferromagnetism.

scholarly journals Copper Oxide Films Deposited by Microwave Assisted Alkaline Chemical Bath

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 968
Author(s):  
Reina Galeazzi Isasmendi ◽  
Isidro Juvenal Gonzalez Panzo ◽  
Crisóforo Morales-Ruiz ◽  
Román Romano Trujillo ◽  
Enrique Rosendo ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Copper Oxide ◽  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
Precursor Solution ◽  
Band Gap Energy ◽  
X Ray ◽  
Gap Energy ◽  
Glass Substrates ◽  
Microwave Assisted

Copper oxide (CuO) films were deposited onto glass substrates by the microwave assisted chemical bath deposition method, and varying the pH of the solution. The pH range was varied from 11.0 to 13.5, and the effects on the film properties were studied. An analytical study of the precursor solution was proposed to describe and understand the chemical reaction mechanisms that take place in the chemical bath at certain pH to produce the CuO film. A series of experiments were performed by varying the parameters of the analytical model from which the CuO films were obtained. The crystalline structure of the CuO films was studied using X-ray diffraction, while the surface morphology, chemical composition, and optical band-gap energy were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, and UV–Vis spectrophotometry, respectively. The CuO films obtained exhibited a monoclinic crystalline phase, nanostructured surface morphology, stoichiometric Cu/O ratio of 50/50 at%, and band-gap energy value of 1.2 eV.

X-ray photoelectron spectroscopy studies of Co-doped ZnO–Ga2O3–SiO2 nano-glass–ceramic composites

2011 ◽  
Vol 257 (9) ◽  
pp. 4291-4295 ◽  
Author(s):  
Xiulan Duan ◽  
Chunfeng Song ◽  
Fapeng Yu ◽  
Duorong Yuan ◽  
Xiaoyu Li
Keyword(s):  
Glass Ceramic ◽  
Photoelectron Spectroscopy ◽  
Ceramic Composites ◽  
X Ray ◽  
Doped Zno ◽  
Spectroscopy Studies ◽  
Co Doped

scholarly journals X-RAY PHOTOELECTRON SPECTROSCOPIC STUDY ON HIGH-ELECTRON-MOBILITY GALLIUM AND HYDROGEN CO-DOPED ZINC OXIDE THIN FILMS

2018 ◽  
Vol 56 (1A) ◽  
pp. 93
Author(s):  
Anh Thanh Tuan Pham
Keyword(s):  
Thin Films ◽  
Electron Mobility ◽  
Photoelectron Spectroscopy ◽  
Lattice Structure ◽  
Hydrogen Plasma ◽  
Crystalline Lattice ◽  
High Electron ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

In this study, gallium and hydrogen co-doped ZnO (HGZO) thin films were investigated. The films were deposited by sputtering from Ga-doped ZnO (GZO) ceramic target in hydrogen and argon plasma. The as-deposited HGZO films possess enhanced electron mobility of 48.6 cm2/Vs as compared to that of 39.4 cm2/Vs of GZO films, sputtered from the same target. Because of insignificant variation in crystallinity, this improvement is attributed to roles of hydrogen in crystalline lattice structure of the films. X-ray photoelectron spectroscopy (XPS) is employed as an essential technique for quantitative analyses and chemical binding states of films constituent elements. The roles of hydrogen are clarified through the binding states of Zn 2p, O 1s and Ga 3d. Obtained results suggest that the films are deposited more effectively in hydrogen plasma. Some point defects such as oxygen vacancies (VO), dangling bonds can be passivated in form of H+VOHO and O–H bonds. As a result, the reduction of scattering centers is indicated as a reason for the mobility improvement of the HGZO films.

Structural, Morphological, Optical and Photocatalytic Properties of Os and N Co-Doped TiO2 Films

2020 ◽  
Vol 853 ◽  
pp. 235-242
Author(s):  
Zhi Li ◽  
Chun Yu Ma
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Rf Magnetron Sputtering ◽  
Photocatalytic Properties ◽  
X Ray ◽  
Force Microscopy ◽  
Co Doping ◽  
Atomic Force ◽  
Co Doped

In the present work, Os and N co-doped TiO2 films were first prepared using a reactive RF magnetron sputtering of Ti–Os metallic target. The effect of Os concentration varying from 0 to 3.0at.% on structure as well as morphology and subsequent changes in optical and photocatalytic properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), optical absorption spectra and photoluminescence (PL) spectroscopy. XRD and SEM results show that the co-doping of Os and N favors the crystal growth of TiO2 and leads to a low anatase thermal stability relative to N monodoping. The band gap of the N/Os co-doped films is reduced from 3.42 eV to 3.22 eV compared with the N-TiO2 film. PL investigation further exhibits the effects of Os doping on the electronic structures and defects in N-TiO2.The photocatalytic activities of the films were evaluated by the degradation of methylene blue in aqueous solution under UV light. It was found that the photocatalytic activity increases with increasing Os content first, and then decreases after the optimal Os content. Therefore, the photocatalytic activity of Os/N co-modified TiO2 photocatalysts can be adjusted by the Os content.

Room-temperature Ferromagnetic Zn0.95Co0.05O Diluted Magnetic Semiconducting Thin Films by Pulsed Laser Deposition

2006 ◽  
Vol 928 ◽  
Author(s):  
Yuebin Zhang ◽  
Qing Liu ◽  
Thirumany Sritharan ◽  
Chee-Lip Gan ◽  
Sean Li
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray ◽  
Doped Zno ◽  
Diluted Magnetic ◽  
Co Doped

ABSTRACTCo-doped ZnO thin films with room-temperature ferromagnetism have been successfully synthesized on (001) Si substrates at 450 °C by pulsed-laser deposition using a Zn0.95Co0.05O ceramic target. Their microstructural properties are carefully studied using atomic force microscopy, x-ray diffraction and high-resolution transmission electron microscopy. The oxidation state of Co and the ratio of Co/Zn are examined by x-ray photoelectron spectroscopy, and magnetic measurements are performed using SQUID. The results show that a single-phase crystalline Co-doped ZnO film was grown with (002) preferential orientation and some edge dislocations formed during the film growth. The origin of room-temperature ferromagnetism is explored. The presence of nanoclusters of any magnetic phase can be ruled out. The dislocations, coupled with oxygen vacancy, may contribute to the ferromagnetic properties in the much diluted magnetic semiconductor.

scholarly journals Formation of ZnO films using the SILAR method

Chemija ◽  
2019 ◽  
Vol 30 (2) ◽  
Author(s):  
Birutė Šimkūnaitė-Stanynienė ◽  
Giedrė Grincienė ◽  
Leonas Naruškevičius ◽  
Loreta Tamašauskaitė-Tamašiūnaitė ◽  
Algirdas Selskis ◽  
...  
Keyword(s):  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Precursor Solution ◽  
Band Gap Energy ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Silar Method ◽  
X Ray ◽  
Glass Substrates ◽  
Layer Adsorption

The thin ZnO films were deposited using the successive ionic layer adsorption and reaction (SILAR) method. The morphology, structure and composition of the thin ZnO films were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The optical properties of the thin ZnO layers, which were deposited onto glass substrates, were investigated using ultraviolet–visible spectrophotometry (UV/Vis). It was found that the optical properties of the ZnO films depend on the composition of anionic precursor solutions, which were used for deposition of the ZnO layers. Moreover, the highest band gap energy of 3.86 eV was obtained for the ZnO layer when the 0.026 mol l–1 Na2B4O7 + 0.002 mol l–1 KMnO4 solution was used as the anionic precursor solution for the deposition of ZnO layers.

Effects of Annealing on Structural and Magnetic Properties of Cobalt Implanted TiO2 Thin Films

2007 ◽  
Vol 999 ◽  
Author(s):  
W. Y. Luk ◽  
Q. Li ◽  
S. P. Wong ◽  
H. P. Ho ◽  
N. Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Room Temperature Ferromagnetism ◽  
Dose Range ◽  
Ion Source ◽  
Fixed Dose ◽  
X Ray ◽  
Co Doped

AbstractSince the observation of room-temperature ferromagnetism (RTFM) in Co-doped anatase TiO2 [1], there have been many reports on the study of the magnetic properties of Co-doped TiO2 prepared by various methods with diversified results. The origin of the RTFM in these systems is still a topic of controversy today. In this work, TiO2 thin films were prepared by RF sputtering onto thermally grown oxide layers on Si substrates. Cobalt implantation was performed using a metal vapor vacuum arc (MEVVA) ion source to various doses ranging from 3×1015 cm-2 to 4×1016 cm-2. Post-implantation annealing was performed in a vacuum chamber at various temperatures ranging from 400°C to 700°C for 2 hours and 4 hours. Characterization of these films as-implanted and after thermal annealing under various conditions was performed using Rutherford backscattering spectrometry, energy filtered and high-resolution transmission electron microscopy, x-ray diffractometry, x-ray photoelectron spectroscopy, and vibrating sample magnetometry. The dependence of the magnetic properties on the implantation and annealing conditions were studied in detail. Clear RTFM properties were observed. The saturation magnetic moment per implanted Co atom (MS) seems to increase with increasing dose within the implantation dose range in this study. At a fixed dose, the MS value also shows a generally increasing trend with increasing annealing temperature and annealing time. Quite a number of samples showed MS values exceeding the bulk Co value of 1.69 ìB/Co significantly and the maximum MS value observed is about 3.16 µB/Co. Such high MS values indicate that the RTFM must not come from Co clusters alone. Possible origins of the RTFM properties will be discussed in conjunction with the structural properties.

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