The Influence of Bi Content on the Properties of Bismuth Ferrite Thin Films Fabricated by Magnetron Sputtering

2013 ◽  
Vol 745-746 ◽  
pp. 131-135
Author(s):  
Hu Rui Yan ◽  
Nuo Fan Ding ◽  
Gang Wu ◽  
Ping Xiong Yang ◽  
Jun Hao Chu ◽  
...  

In the process of BiFeO3 film preparation by magnetron sputtering, Bi element is volatile, leading to the films which often appear impurity phases. Therefore, Both Bi excessive 5% (B1.05FO) and 8% (B1.08FO) BFO film in Si substrate were prepared by magnetron sputtering. X-Ray Diffraction (XRD) results showed that the BFO thin films fabricated in the Si substrate are perovskite structure, that the B1.08FO film appeared less impurity phases than B1.05FO film, and that stress due to substrate lattice mismatch caused the shift of XRD patterns. In Raman study, it was concluded that both B1.08FO film and B1.05FO film appeared ten Raman peaks in the range from 50cm-1 to 800cm-1, and that B1.08FO Raman peaks intensity was stronger in 137.1cm-1.168.5cm-1 and 215.3cm-1. Spectroscopic ellipsometry test showed that the refractive index and the extinction coefficient of B1.05FO film were 2.25 and 0.07 respectively in 600 nm with 2.67eV of energy gap; the refractive index and the extinction coefficient of B1.08FO film were 2.14 and 0.05 in 600 nm respectively with 2.71eV of energy gap. Atomic Force Microscope (AFM) was used to characterize the film surface morphology, finding that the B1.08FO film prepared in Si substrate was denser while grain size and surface roughness were smaller.

2013 ◽  
Vol 446-447 ◽  
pp. 259-262
Author(s):  
J.H. Gu ◽  
T. Zhang ◽  
Z.Y. Zhong ◽  
C.Y. Yang ◽  
J. Hou

Aluminium doped zinc oxide (AZO) thin films were prepared by magnetron-sputtering. The optical and structural properties of the films were investigated by optical transmission spectra and X-ray diffraction (XRD) measurements, respectively. The results indicate that the AZO films have hexagonal wurtzite structure with highly c-axis preferred orientation. The optical and structural properties of the films are observed to be subjected to the argon pressure. The AZO film prepared at the argon pressure of 0.5 Pa exhibits the largest crystallite size and the highest average visible transmittance. Also, the refractive index and optical energy-gap of the films were determined by optical characterization methods. The dispersion behavior of the refractive index was studied using the Sellmeier’s dispersion model.


2013 ◽  
Vol 804 ◽  
pp. 3-7
Author(s):  
Chao Zhan ◽  
Wen Jian Ke ◽  
Xin Ming Li ◽  
Wan Li Du ◽  
Li Juan Wang ◽  
...  

Cubic ZnTiO3thin films have been prepared by radio frequency magnetron sputtering on n-type (100) Si substrate at different temperatures. The morphological and optical properties of ZnTiO3films in relation to substrate temperatures are investigated by spectroscopic ellipsometry (SE) and AFM as well as SEM in detail. X-ray diffraction (XRD) measurement shows that all the films have a cubic phase structure and the optimum substrate temperature to form crystalline ZnTiO3thin film is 250 °C. Through SEM and AFM, the particle size in thin films and film surface roughness increase with increasing the substrate temperature. Based on a parameterized TaucLorentz dispersion model, the optical constants and surface roughness of ZnTiO3films related to the substrate temperature are systematically extracted by SE measurement. The surface roughness of the film measured from AFM agrees well with result extracted from SE, which proved that the established SE model is reasonable. With increasing substrate temperature, the refractive index decreases and the main factor in determining the refractive index was deduced to be the surface roughness related to the film packing density. The extinction coefficient of the samples is close to zero, but increases slightly with the increase of the substrate temperature, which is due to the enhancement of scattering effect in the crystalline ZnTiO3film.


2021 ◽  
Vol 19 (49) ◽  
pp. 22-31
Author(s):  
Wasan A. Al-Taa'y ◽  
Bushra A. Hasan

The properties of structural and optical of pure and doped nano titanium dioxide (TiO2) films, prepared using chemical spray pyrolysis (CPS) technique, with different nanosize nickel oxide (NiO) concentrations in the range (3-9)wt% have been studied. X-Ray diffraction (XRD) technique where using to analysis the structure properties of the prepared thin films. The results revealed that the structure properties of TiO2 have polycrystalline structure with anatase phase. The parameters, energy gap, extinction coefficient, refractive index, real and imaginary parts were studied using absorbance and transmittance measurements from a computerized ultraviolet visible spectrophotometer (Shimadzu UV-1601 PC) in the wavelengths range (300-800)nm. Optical properties of TiO2 affected by the adding of NiO impurity where the transmittance increased as NiO concentration increased but with more adding the transmittance returned to decrease again. It was found the extinction coefficient, refractive index, real and imaginary parts values decreased with increasing doping percentage up to 7% and then increases occur one more again at 9%. Energy gap values increased after doping with NiO where the values lies in the range was 3.31 to 3.51 eV .


2020 ◽  
pp. 2050054
Author(s):  
RADOUANE GRAINE ◽  
KHOULOUD BEDOUD ◽  
NADJETTE SEHAB ◽  
DJAMEL ZELMATI

In this study, Anatase thin films of titanium dioxide (TiO[Formula: see text] are deposited by the Direct Current (DC) magnetron sputtering technique on glass substrate for future application in gas sensors. In our work, we focused and discussed the effect of various substrate temperatures [Formula: see text]C, [Formula: see text]C and [Formula: see text]C, and film thicknesses 142, 220 and 410[Formula: see text]nm, respectively, in order to study the structural and optical properties of the TiO2 thin films. The crystalline structure and optical properties of TiO2 nanoparticles were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Atomic Force Microscopy (AFM), Raman spectroscopy and UV–visible spectroscopy. The formation of the Anatase TiO2 with Tetragonal crystal structure has been confirmed with XRD. UV–visible spectrophotometry characterization of the developed thin films showed that all the films had an optical transmission greater than 92% in the visible region. In addition, the obtained direct and indirect optical band gaps using the Tauc plot are 3.66, 3.34[Formula: see text]eV at [Formula: see text]C 3.74, 3.37[Formula: see text]eV at [Formula: see text]C and 3.71, 3.37[Formula: see text]eV at [Formula: see text]C, respectively. Forouhi–Bloomer (FB) physical model has been used to obtain the refractive index and extinction coefficient by fitting theoretical transmittance curves to experimental ones. The optical refractive index is found to vary from 2.350 for [Formula: see text]C, 2.1499 for [Formula: see text]C and 2.1420 for [Formula: see text]C. Moreover, we have obtained an extinction coefficient [Formula: see text] ([Formula: see text] of around [Formula: see text] for both substrate temperatures [Formula: see text]C and [Formula: see text]C, and around [Formula: see text] for the [Formula: see text]C.


Author(s):  
Wasmaa Abdulsattar Jabbar

Copper oxide prepared with various contains of Manganese by chemical spray pyrolysis. Some optical properties are studied from recording the absorption spectra via UV-Visible spectrophotometer in the range of 460-900 nm. The absorbance increased with increasing Mn-contain in the CuO thin films, and the absorption coefficient. Extinction coefficient and refractive index are decreased with increasing Mn-contain in the CuO thin films, also the energy gap shifted from 2 eV to 1.91 eV after 4%Mn additive.


2017 ◽  
Vol 35 (2) ◽  
pp. 335-345 ◽  
Author(s):  
A.M. Abd-Elnaiem ◽  
M. Mohamed ◽  
R.M. Hassan ◽  
A.A. Abu-Sehly ◽  
M.A. Abdel-Rahim ◽  
...  

Abstract Chalcogenide glasses have attracted much attention largely due to their interesting physical and chemical properties. Though few published articles exist on the As-Te system, little is known about the optical properties of eutectic or near eutectic composition of As-Te system upon heat treatment. Therefore, this paper reports the effects of annealing temperature on the structural and optical parameters of As30Te70 thin films. The bulk and thin films of 150 nm thick As30Te70 chalcogenide glasses were prepared by melt-quenching and thermal evaporation techniques, respectively. The glass transition and crystallization reactions of the bulk samples were investigated using differential scanning calorimetry (DSC). The influence of annealing temperature on the transformation of the crystal structure was studied by X-ray diffraction (XRD), while the surface morphology of the annealed samples was examined using scanning electron microscope (SEM). The optical band gap, refractive index and extinction coefficient were also calculated. The DSC scans showed that the melting temperature remains constant at 636.56 K. In addition, other characteristic temperatures such as the glass transition temperature, the onset crystallization temperature, and the crystallization peak temperature increase with increasing the heating rate. The crystalline phases for the as-prepared and annealed films consist of orthorhombic As, hexagonal Te, and monoclinic As2Te3 phases. Furthermore, the average crystallite size, strain, and dislocation density depend on the annealing temperature. The optical absorption results revealed that the investigated films have a direct transition, and their optical energy gap decreases from 1.82 eV to 1.49 eV as the annealing temperature increases up to 433 K. However, the refractive index, extinction coefficient, dielectric constant and the ratio of free carrier concentration to its effective mass, increase with increasing the annealing temperature.


Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.


2021 ◽  
Vol 120 ◽  
pp. 111382
Author(s):  
Yu.A. Kuznetsova ◽  
A.F. Zatsepin ◽  
N.V. Gavrilov

2018 ◽  
Vol 36 (4) ◽  
pp. 717-721
Author(s):  
Piotr Potera ◽  
Grzegorz Wisz ◽  
Łukasz Szyller

AbstractThe growth of AlN layers on glass substrates using magnetron sputtering method was performed and the grown layers were subjected to optical measurements. Transmission spectra of the layers grown at different content of N2 in the atmosphere were obtained. The transmission spectra as well as energy gap depended on N2 content. The annealing of the layers in air led to transmission changes and influenced energy gap and refractive index values.


2007 ◽  
Vol 124-126 ◽  
pp. 999-1002 ◽  
Author(s):  
Han Na Cho ◽  
Jang Woo Lee ◽  
Su Ryun Min ◽  
Chee Won Chung

Indium zinc oxide (IZO) thin films were deposited on a glass substrate by radio frequency (rf) reactive magnetron sputtering method. As the rf power increased, the deposition rate and resistivity increased while the optical transmittance decreased owing to the increase of grain size. With increasing gas pressure, the resistivity increased and the transmittance decreased. Atomic force microscopy and scanning electron microscopy were employed to observe the film surface. The IZO films displayed a resistivity of 3.8 × 10-4 Ω cm and a transmittance of about 90% in visible region.


Sign in / Sign up

Export Citation Format

Share Document