Nanostructured Hematite Prepared by Thermal Oxidation of Iron

2016 ◽  
Vol 694 ◽  
pp. 208-212 ◽  
Author(s):  
Syahriza Ismail ◽  
Nur Syafini Saad ◽  
Jeeferie Abd Razak
Keyword(s):  
Raman Spectroscopy ◽  
Iron Oxide ◽  
Thermal Oxidation ◽  
Surface Diffusion ◽  
Structural Properties ◽  
Diffusion Mechanism ◽  
Morphological Observation ◽  
Oxide Nanowires ◽  
Oxidation Period ◽  
Heating Duration

This paper reports on the synthesis of iron oxide nanowires using thermal oxidation of iron. The α-Fe2O3 (hematite) and Fe3O4 (magnetite) were successfully formed using this method. The morphological observation was done through the FESEM, while the XRD, EDX and Raman spectroscopy were used to determine the physical and structural properties of the produced nanostructures. It was found that the peaks intensities relative to the hematite, increased with the extent of oxidation period. The growth and final morphology of hematite was significantly controlled by the heating duration. A surface diffusion mechanism for nano-hematite growth was then proposed to account for the growth phenomena of this nanostructured formation.

scholarly journals Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Ana M. Herrero ◽  
Claudia Ruiz-Capillas
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Structural Changes ◽  
Protein Secondary Structure ◽  
Lipid Phase ◽  
Α Helix ◽  
Β Sheet ◽  
Shed Light ◽  
Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

2021 ◽  
Author(s):  
Linfei Yang ◽  
Jianjun Jiang ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Meiling Hong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Theoretical Calculations ◽  
Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

scholarly journals Iron Oxide-Coupled Graphite/Fe–Si Steel Structure for Analog Computing from Recycling Principle

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 607
Author(s):  
Roberto Baca-Arroyo
Keyword(s):  
Raman Spectroscopy ◽  
Iron Oxide ◽  
Steel Structure ◽  
Oxide Thin Film ◽  
Coating Film ◽  
Analog Computing ◽  
Current Voltage ◽  
Graphite Structure ◽  
Graphite Lattice ◽  
Steel Foils

Analog computing from recycling principle for next circular economy scenario has been studied with an iron oxide-coupled graphite/Fe–Si steel structure which was built using recycled waste materials, such as lead pencil and 3% Si steel (Fe–Si steel) foils. Proximity phenomena, such as disordered structure of iron oxide and magnetostriction-induced conduction, inside graphite lattice resulted in functional properties to advance analog architectures. Thermal oxidation was the synthesis route to produce iron oxide as coating film on Fe–Si steel foil, whose structure properties were validated by Raman spectroscopy where phase formation of hematite, α-Fe2O3, resulted as iron oxide thin-film. Three graphite layers with different compositions were also analyzed by Raman spectroscopy and used for studying electrical conduction in Fe–Si steel/α-Fe2O3/graphite structure from current–voltage plots at room temperature.

On the growth of copper oxide nanowires by thermal oxidation near the threshold temperature at atmospheric pressure

2021 ◽  
pp. 161130
Author(s):  
Calin Constantin Moise ◽  
Laura-Bianca Enache ◽  
Veronica Anastasoaie ◽  
Oana Andreea Lazar ◽  
Geanina Valentina Mihai ◽  
...  
Keyword(s):  
Copper Oxide ◽  
Thermal Oxidation ◽  
Atmospheric Pressure ◽  
Threshold Temperature ◽  
Oxide Nanowires

Residual Stress Measurement in Silicon Substrate After Local Thermal Oxidation Using Microscopic Raman Spectroscopy

1991 ◽  
Vol 226 ◽  
Author(s):  
Hideo Miura ◽  
Hiroshi Sakata ◽  
Shinji Sakata Merl
Keyword(s):  
Residual Stress ◽  
Raman Spectroscopy ◽  
Tensile Stress ◽  
Oxide Film ◽  
Film Thickness ◽  
Silicon Dioxide ◽  
Thermal Oxidation ◽  
Silicon Substrate ◽  
Nitride Film ◽  
Oxide Film Thickness

AbstractThe residual stress in silicon substrates after local thermal oxidation is discussed experimentally using microscopic Raman spectroscopy. The stress distribution in the silicon substrate is determined by three main factors: volume expansion of newly grown silicon–dioxide, deflection of the silicon–nitride film used as an oxidation barrier, and mismatch in thermal expansion coefficients between silicon and silicon dioxide.Tensile stress increases with the increase of oxide film thickness near the surface of the silicon substrate under the oxide film without nitride film on it. The tensile stress is sometimes more than 100 MPa. On the other hand, a complicated stress change is observed near the surface of the silicon substrate under the nitride film. The tensile stress increases initially, as it does in the area without nitride film on it. However, it decreases with the increase of oxide film thickness, then the compressive stress increases in the area up to 170 MPa. This stress change is explained by considering the drastic structural change of the oxide film under the nitride film edge during oxidation.

Unravelling transient phases during thermal oxidation of copper for dense CuO nanowire growth

CrystEngComm ◽  
2014 ◽  
Vol 16 (16) ◽  
pp. 3264-3267 ◽  
Author(s):  
Fei Wu ◽  
Yoon Myung ◽  
Parag Banerjee
Keyword(s):  
Raman Spectroscopy ◽  
Grain Boundaries ◽  
Thermal Oxidation ◽  
High Purity ◽  
Direct Evidence ◽  
Nanowire Growth ◽  
Cupric Ion ◽  
Cuo Nanowire ◽  
Transient Phases

Direct evidence of cupric ion outdiffusion through grain boundaries during thermal oxidation of high purity Cu is obtained using Raman spectroscopy.

Structural properties of GaNAs nanowires probed by micro-Raman spectroscopy

2015 ◽  
Vol 31 (2) ◽  
pp. 025002 ◽  
Author(s):  
S Filippov ◽  
F Ishikawa ◽  
W M Chen ◽  
I A Buyanova
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Micro Raman Spectroscopy
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