scholarly journals Influence of Post-Annealing on the Structural and Nanomechanical Properties of Co Thin Films

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 180 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Cheng-Tang Pan ◽  
Ying-Xu Lu ◽  
Sheng-Rui Jian ◽  
Huang-Wei Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Face Centered Cubic ◽  
Ambient Conditions ◽  
Nanomechanical Properties ◽  
Glass Substrates ◽  
Hexagonal Close Packed ◽  
Nanoindentation Measurement ◽  
Different Temperatures ◽  
Face Centered

The correlations between the microstructure and nanomechanical properties of a series of thermal annealed Co thin films were investigated. The Co thin films were deposited on glass substrates using a magnetron sputtering system at ambient conditions followed by subsequent annealing conducted at various temperatures ranging from 300 °C to 800 °C. The XRD results indicated that for annealing temperature in the ranged from 300 °C to 500 °C, the Co thin films were of single hexagonal close-packed (hcp) phase. Nevertheless, the coexistence of hcp-Co (002) and face-centered cubic (fcc-Co (111)) phases was evidently observed for films annealed at 600 °C. Further increasing the annealing temperature to 700 °C and 800 °C, the films evidently turned into fcc-Co (111). Moreover, significant variations in the hardness and Young’s modulus are observed by continuous stiffness nanoindentation measurement for films annealed at different temperatures. The correlations between structures and properties are discussed.

scholarly journals Annealing-Driven Microstructural Evolution and Its Effects on the Surface and Nanomechanical Properties of Cu-Doped NiO Thin Films

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 107 ◽  
Author(s):  
San-Ho Wang ◽  
Sheng-Rui Jian ◽  
Guo-Ju Chen ◽  
Huy-Zu Cheng ◽  
Jenh-Yih Juang
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Annealing Temperature ◽  
Film Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanomechanical Properties ◽  
Glass Substrates ◽  
Structural Surface ◽  
Diffraction Peaks

The effects of annealing temperature on the structural, surface morphological and nanomechanical properties of Cu-doped (Cu-10 at %) NiO thin films grown on glass substrates by radio-frequency magnetron sputtering are investigated in this study. The X-ray diffraction (XRD) results indicated that the as-deposited Cu-doped NiO (CNO) thin films predominantly consisted of highly defective (200)-oriented grains, as revealed by the broadened diffraction peaks. Progressively increasing the annealing temperature from 300 to 500 °C appeared to drive the films into a more equiaxed polycrystalline structure with enhanced film crystallinity, as manifested by the increased intensities and narrower peak widths of (111), (200) and even (220) diffraction peaks. The changes in the film microstructure appeared to result in significant effects on the surface energy, in particular the wettability of the films as revealed by the X-ray photoelectron spectroscopy and the contact angle of the water droplets on the film surface. The nanoindentation tests further revealed that both the hardness and Young’s modulus of the CNO thin films increased with the annealing temperature, suggesting that the strain state and/or grain boundaries may have played a prominent role in determining the film’s nanomechanical characterizations.

scholarly journals Effect of Annealing on the Nanostructure Formation in Alkoxy Substituted Phthalocyanine Thin Films

2012 ◽  
Vol 9 (4) ◽  
pp. 1992-1999
Author(s):  
Vinu. T. Vadakel ◽  
C. S. Menon
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Annealing Temperature ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Sem Images ◽  
Glass Substrates ◽  
Heat Treated ◽  
Different Temperatures ◽  
Post Deposition

Vacuum deposited 2,3,9,10,16,17,23,24-octakis (octyloxy) phthalocyanine (H2PcOC8) thin films on glass substrates have exhibited a change on their surface morphology with the post deposition annealing temperature under normal atmosphere. These films have been characterized by optical absorptions and Scanning Electron Microscopy. SEM images also have shown nano-rod like structures for the samples annealed at different temperatures. The variation of optical band gap with annealing temperature is determined. The direct and allowed optical band gap energy has been evaluated from the α2versus hυ plots. The electrical conductivity of the films at various heat treated samples are also studied. The activation energies are determined from the Arrhenius plots of lnσ versus 1000/T . It shows variation with the annealing temperature.

scholarly journals Annealing Effect on the SnSe Nanocrystalline Thin Films and the Photovoltaic Properties of the p-SnSe/n-Si Heterojunction Solar Cells

2021 ◽  
Vol 8 (2) ◽  
pp. 41-49
Author(s):  
Ghuzlan Sarhan Ahmed ◽  
Bushra K. H. Al-Maiyaly ◽  
Seham Hasan Salman ◽  
Rajaa Faisal Rabeea
Keyword(s):  
Thin Films ◽  
Hall Effect ◽  
Annealing Temperature ◽  
Reverse Bias Voltage ◽  
Photovoltaic Properties ◽  
Heterojunction Solar Cells ◽  
Glass Substrates ◽  
Nano Crystalline ◽  
Different Temperatures ◽  
Hall Effect Measurements

A thin film of SnSe were deposited by thermal evaporation technique on 400 ±20 nm thick glass substrates of these films were annealed at different temperatures (100,150,200 ⁰C), The effect of annealing on the characteristics of the nano crystalline SnSe thin films was investigated using XRD, UV-VIS absorption spectroscopy, Atomic Force Microscope (AFM), and Hall effect measurements. The results of X-ray displayed that all the thin films have polycrystalline and orthorhombic structure in nature, while UV-VIS study showed that the SnSe has direct band gap of nano crystalline and it is changed from 60.12 to 94.70 nm with increasing annealing temperature. Hall effect measurements showed that all the films have a positive Hall coefficient, which means that the conductivity of the films is p-type. The conductivity of SnSe films was increased with increasing annealing temperatures (except that at 200⁰C). The I-V characteristics under illumination for the "p-SnSe/n-Si” solar cell displayed an increase in conversion efficiency with increasing annealing temperature from R.T to 150⁰C, while at 200⁰C, this efficiency was decreased. The measurements of the C-V characteristics displayed that all junctions were abrupt type. It is clear from C-V measurements that the capacitance decreased with increasing reverse bias voltage which leads to an increase in the depletion width.

scholarly journals Ion irradiation induced phase transformation in gold nanocrystalline films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pranav K. Suri ◽  
James E. Nathaniel ◽  
Nan Li ◽  
Jon K. Baldwin ◽  
Yongqiang Wang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Ion Irradiation ◽  
Face Centered Cubic ◽  
Ambient Conditions ◽  
Free Standing ◽  
Hexagonal Close Packed ◽  
Transmission Electron ◽  
Precession Electron Diffraction ◽  
Radiation Induced ◽  
Face Centered

Abstract Gold is a noble metal typically stable as a solid in a face-centered cubic (FCC) structure under ambient conditions; however, under particular circumstances aberrant allotropes have been synthesized. In this work, we document the phase transformation of 25 nm thick nanocrystalline (NC) free-standing gold thin-film via in situ ion irradiation studied using atomic-resolution transmission electron microscopy (TEM). Utilizing precession electron diffraction (PED) techniques, crystallographic orientation and the radiation-induced relative strains were measured and furthermore used to determine that a combination of surface and radiation-induced strains lead to an FCC to hexagonal close packed (HCP) crystallographic phase transformation upon a 10 dpa radiation dose of Au4+ ions. Contrary to previous studies, HCP phase in nanostructures of gold was stabilized and did not transform back to FCC due to a combination of size effects and defects imparted by damage cascades.

Diffraction Stress Analysis of Fiber Textured Ti Thin Films Undergoing hcp - fcc Phase Transformation

2013 ◽  
Vol 768-769 ◽  
pp. 257-263
Author(s):  
Jay Chakraborty
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Stress Analysis ◽  
Group Method ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Hexagonal Close Packed ◽  
Face Centered ◽  
Fcc Phase ◽  
Ti Films

X-ray diffraction stress analysis by crystallite group method (CGM) has been employed in case of simultaneously strong and sharp fiber textured Ti thin films. These Ti films exhibit thickness dependent hcp-fcc phase transformation [Ref. 1]. Diffraction stress analysis has also been attempted by d-sin2 method for strongly textured face centered cubic (fcc) and hexagonal close packed (hcp) Ti phases. For hcp Ti phase, the results of stress analysis by CGM are compared with those obtained from d-sin2 method. It is found that the stress values in hcp Ti phases obtained from CGM considerably differ from the stresses obtained from d-sin2 method in some of the Ti films. Observed differences have been explained and possible sources of errors in d-sin2 method and CGM stress analysis have been discussed.

scholarly journals Structural, Electrical, and Optical Properties of PbTe Thin Films Prepared by Simple Flash Evaporation Method

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Lakshmanan Kungumadevi ◽  
Ramakrishnan Sathyamoorthy
Keyword(s):  
Thin Films ◽  
Optical Constants ◽  
Lead Telluride ◽  
Blue Shift ◽  
Face Centered Cubic ◽  
Flash Evaporation ◽  
Electrical And Optical Properties ◽  
Evaporation Method ◽  
Glass Substrates ◽  
Face Centered

Lead telluride (PbTe) films have been prepared on glass substrates by flash evaporation method. Structure of the film is found to possess stable face-centered cubic (fcc) NaCl phase in which the grains predominantly grow in the direction of (200) plane. The calculated grain size was in the range 19 nm. The electrical resistivity as a function of temperature was measured using four-probe technique. The electrical conductivity was calculated, and the value is found to be from 67.11 to 344.82 S/cm in the temperature range 303–453 K. The value of mobility was evaluated, and it is found to be0.329×10-3 cm2·V−1 S−1. An optical study reveals that the PbTe thin films exhibit large blue shift. The optical constants such as absorption coefficient and refractive index have been estimated, and the results are discussed.

scholarly journals Stability and equation of state of face-centered cubic and hexagonal close packed phases of argon under pressure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agnès Dewaele ◽  
Angelika D. Rosa ◽  
Nicolas Guignot ◽  
Denis Andrault ◽  
João Elias F. S. Rodrigues ◽  
...  
Keyword(s):  
Equation Of State ◽  
Single Crystal ◽  
Single Crystal Sample ◽  
Moderate Pressure ◽  
Face Centered Cubic ◽  
Experimental Conditions ◽  
Crystal Sample ◽  
Hexagonal Close Packed ◽  
Face Centered ◽  
Fcc Phase

AbstractThe compression of argon is measured between 10 K and 296 K up to 20 GPa and and up to 114 GPa at 296 K in diamond anvil cells. Three samples conditioning are used: (1) single crystal sample directly compressed between the anvils, (2) powder sample directly compressed between the anvils, (3) single crystal sample compressed in a pressure medium. A partial transformation of the face-centered cubic (fcc) phase to a hexagonal close-packed (hcp) structure is observed above 4.2–13 GPa. Hcp phase forms through stacking faults in fcc-Ar and its amount depends on pressurizing conditions and starting fcc-Ar microstructure. The quasi-hydrostatic equation of state of the fcc phase is well described by a quasi-harmonic Mie–Grüneisen–Debye formalism, with the following 0 K parameters for Rydberg-Vinet equation: $$V_0$$ V 0 = 38.0 Å$$^3$$ 3 /at, $$K_0$$ K 0 = 2.65 GPa, $$K'_0$$ K 0 ′ = 7.423. Under the current experimental conditions, non-hydrostaticity affects measured P–V points mostly at moderate pressure ($$\le$$ ≤ 20 GPa).

scholarly journals Optimizing the Properties of La0.8Sr0.2CrO3 Thin Films through Post-Annealing for High-Temperature Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1802
Author(s):  
Dan Liu ◽  
Peng Shi ◽  
Yantao Liu ◽  
Yijun Zhang ◽  
Bian Tian ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Annealing Temperature ◽  
Rf Sputtering ◽  
Maximum Size ◽  
Cross Sectional ◽  
Post Annealing ◽  
Maximum Conductivity ◽  
Different Temperatures ◽  
Post Annealing Temperature

La0.8Sr0.2CrO3 (0.2LSCO) thin films were prepared via the RF sputtering method to fabricate thin-film thermocouples (TFTCs), and post-annealing processes were employed to optimize their properties to sense high temperatures. The XRD patterns of the 0.2LSCO thin films showed a pure phase, and their crystallinities increased with the post-annealing temperature from 800 °C to 1000 °C, while some impurity phases of Cr2O3 and SrCr2O7 were observed above 1000 °C. The surface images indicated that the grain size increased first and then decreased, and the maximum size was 0.71 μm at 1100 °C. The cross-sectional images showed that the thickness of the 0.2LSCO thin films decreased significantly above 1000 °C, which was mainly due to the evaporation of Sr2+ and Cr3+. At the same time, the maximum conductivity was achieved for the film annealed at 1000 °C, which was 6.25 × 10−2 S/cm. When the thin films post-annealed at different temperatures were coupled with Pt reference electrodes to form TFTCs, the trend of output voltage to first increase and then decrease was observed, and the maximum average Seebeck coefficient of 167.8 µV/°C was obtained for the 0.2LSCO thin film post-annealed at 1100 °C. Through post-annealing optimization, the best post-annealing temperature was 1000 °C, which made the 0.2LSCO thin film more stable to monitor the temperatures of turbine engines for a long period of time.

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