scholarly journals Raman Spectra of High-κDielectric Layers Investigated with Micro-Raman Spectroscopy Comparison with Silicon Dioxide

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
P. Borowicz ◽  
A. Taube ◽  
W. Rzodkiewicz ◽  
M. Latek ◽  
S. Gierałtowska
Keyword(s):  
Raman Spectroscopy ◽  
Silicon Dioxide ◽  
Raman Spectra ◽  
Hafnium Oxide ◽  
Silicon Oxide ◽  
Temperature Treatment ◽  
Silicon Dioxide Layer ◽  
Micro Raman Spectroscopy ◽  
Lutetium Oxide ◽  
Three Samples

Three samples with dielectric layers from high-κdielectrics, hafnium oxide, gadolinium-silicon oxide, and lanthanum-lutetium oxide on silicon substrate were studied by Raman spectroscopy. The results obtained for high-κdielectrics were compared with spectra recorded for silicon dioxide. Raman spectra suggest the similarity of gadolinium-silicon oxide and lanthanum-lutetium oxide to the bulk nondensified silicon dioxide. The temperature treatment of hafnium oxide shows the evolution of the structure of this material. Raman spectra recorded foras-depositedhafnium oxide are similar to the results obtained for silicon dioxide layer. After thermal treatment especially at higher temperatures (600°C and above), the structure of hafnium oxide becomes similar to the bulk non-densified silicon dioxide.

Raman Spectra of Human Dental Calculus

1993 ◽  
Vol 72 (12) ◽  
pp. 1609-1613 ◽  
Author(s):  
H. Tsuda ◽  
J. Arends
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Octacalcium Phosphate ◽  
Spot Size ◽  
Spectral Features ◽  
Dental Calculus ◽  
Micro Raman Spectroscopy ◽  
Vibrational Bands ◽  
First Time ◽  
Mineral Constituents

Raman spectra of human dental calculus have been observed for the first time by use of micro-Raman spectroscopy. The spectral features of calculus were influenced easily by heating caused by laser irradiation. Therefore, the measurements were carried out at relatively low power (5 mW, 1-μm spot size). The spectra could be characterized as phosphate vibrational bands due to the v1, v2, v 3, and v4 modes. The overall spectral features did not resemble those of pure minerals such as brushite, octacalcium phosphate, and hydroxyapatite. There were spectral differences among mixed calculus particles obtained from 18 adults, probably due to variations in local mineral composition and differences among patients. However, the averaged spectral features did not vary significantly with formation period from 1 to 6 months. Freshly removed and stored (5-11 months) calculus also gave comparable Raman spectra. Measurements on a fractured sample indicated that Raman spectra at saliva and dentin interfaces are nearly identical, and major mineral constituents may not vary significantly along the growth axis of calculus.

scholarly journals Raman Spectroscopy as a Potential Tool for Detection of Brucella spp. in Milk

2012 ◽  
Vol 78 (16) ◽  
pp. 5575-5583 ◽  
Author(s):  
Susann Meisel ◽  
Stephan Stöckel ◽  
Mandy Elschner ◽  
Falk Melzer ◽  
Petra Rösch ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Cell ◽  
Raman Spectra ◽  
Detection System ◽  
Support Vector ◽  
Promising Alternative ◽  
Content Type ◽  
Micro Raman Spectroscopy ◽  
Genotypic Characteristics ◽  
Potential Tool

ABSTRACTDetection ofBrucella, causing brucellosis, is very challenging, since the applied techniques are mostly time-demanding and not standardized. While the common detection system relies on the cultivation of the bacteria, further classical typing up to the biotype level is mostly based on phenotypic or genotypic characteristics. The results of genotyping do not always fit the existing taxonomy, and misidentifications between genetically closely related genera cannot be avoided. This situation gets even worse, when detection from complex matrices, such as milk, is necessary. For these reasons, the availability of a method that allows early and reliable identification of possibleBrucellaisolates for both clinical and epidemiological reasons would be extremely useful. We evaluated micro-Raman spectroscopy in combination with chemometric analysis to identifyBrucellafrom agar plates and directly from milk: prior to these studies, the samples were inactivated via formaldehyde treatment to ensure a higher working safety. The single-cell Raman spectra of differentBrucella,Escherichia,Ochrobactrum,Pseudomonas, andYersiniaspp. were measured to create two independent databases for detection in media and milk. Identification accuracies of 92% forBrucellafrom medium and 94% forBrucellafrom milk were obtained while analyzing the single-cell Raman spectra via support vector machine. Even the identification of the other genera yielded sufficient results, with accuracies of >90%. In summary, micro-Raman spectroscopy is a promising alternative for detectingBrucella. The measurements we performed at the single-cell level thus allow fast identification within a few hours without a demanding process for sample preparation.

scholarly journals Meridianiite detected in ice

2009 ◽  
Vol 55 (189) ◽  
pp. 117-122 ◽  
Author(s):  
F. Elif Genceli ◽  
Shinichirou Horikawa ◽  
Yoshinori Iizuka ◽  
Toshimitsu Sakurai ◽  
Takeo Hondoh ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Low Temperature ◽  
Sea Ice ◽  
Magnesium Sulfate ◽  
Raman Spectra ◽  
Sulfate Salt ◽  
Micro Raman Spectroscopy ◽  
Naturally Occurring ◽  
Formation History ◽  
History Of

AbstractInclusions affect the behavior of ice, and their characteristics help us understand the formation history of the ice. Recently, a low-temperature magnesium sulfate salt was discovered. This paper describes this naturally occurring MgSO4·11H2O mineral, meridianiite, derived from salt inclusions in sea ice of Lake Saroma, Japan and in Antarctic continental core ice. Its occurrence is confirmed by using micro-Raman spectroscopy to compare Raman spectra of synthetic MgSO4·11H2O with those of the inclusions.

scholarly journals Investigation of thermostability of Mo6S3I6 nanowires using Raman spectroscopy

2009 ◽  
Vol 63 (3) ◽  
pp. 217-220
Author(s):  
Jelena Todorovic ◽  
Dejan Djokic ◽  
Zorana Dohcevic-Mitrovic ◽  
Dragan Mihailovic ◽  
Zoran Popovic
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Room Temperature ◽  
Group Analysis ◽  
Temperature Treatment ◽  
Incident Laser ◽  
Chevrel Phase ◽  
Incident Laser Power ◽  
Raman Modes ◽  
Good Agreement

The thermostability (phase stability) of Mo6S3I6 nanowires was investigated by Raman spectroscopy, varying the incident laser power (1-9 mW) or by gradual heating of the sample from room temperature to 600?C. We have noticed 18 Raman modes in the room temperature Raman spectra, which is in good agreement with the factor group analysis prediction for P1 space group. We confirmed that the vibrations of Mo6S8 clusters dominate in vibrational properties of the Mo6S3I6 nanostructure, since nanowires Raman spectra are similar to Chevrel phase Raman spectra. During the temperature treatment, it was established that in the temperature range between 300 and 400?C a new Raman mode appeares. This mode can be ascribed to molybdenum oxide (MoO3). With further temperature increase, the intensity of this mode increases, drawing a conclusion that at temperature above 300?C the phase separation takes place in this system followed by a formation of oxide layer.

Micro-Raman Characterization of Unusual Defect Structure in Arsenic-Implanted Silicon

1999 ◽  
Vol 588 ◽  
Author(s):  
David D. Tuschel ◽  
James P. Lavine
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Defect Structure ◽  
Optical Mode ◽  
Micro Raman Spectroscopy ◽  
Lattice Damage ◽  
Spatially Varying ◽  
Raman Characterization ◽  
Extensive Damage

AbstractRaman spectroscopy has often been used to study the damage to semiconductors induced by ion implantation. Off-axis, macro-Raman spectra reveal extensive damage to the silicon lattice, consistent with many literature reports. However, when the same samples were analyzed in the backscattering mode by micro-Raman spectroscopy, evidence was found for orientational dependent lattice damage and an unusual defect structure. P/O micro-Raman spectra reveal the spatially-varying appearance of a band between 505 and 510 cm−1 always accompanied by that of the silicon optical mode at 520 cm−1.

scholarly journals Electrical and Optical Properties of Silicon Oxide Lignin Polylactide (SiO2-L-PLA)

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1354
Author(s):  
Jacek Fal ◽  
Katarzyna Bulanda ◽  
Julian Traciak ◽  
Jolanta Sobczak ◽  
Rafał Kuzioła ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electrical Properties ◽  
Injection Molding ◽  
Silicon Dioxide ◽  
Silicon Oxide ◽  
Logarithmic Scale ◽  
Melt Mixing ◽  
Three Samples ◽  
Vis Spectroscopy ◽  
Mass Fractions

This paper presents a study on the electrical properties of new polylactide-based nanocomposites with the addition of silicon-dioxide–lignin nanoparticles and glycerine as a plasticizer. Four samples were prepared with nanoparticle mass fractions ranging between 0.01 to 0.15 (0.01, 0.05, 0.10, and 0.15), and three samples were prepared without nanoparticle filler—unfilled and unprocessed polylactide, unfilled and processed polylactide, and polylactide with Fusabond and glycerine. All samples were manufactured using the melt mixing extrusion technique and injection molding. Only the unfilled and unprocessed PLA sample was directly prepared by injection molding. Dielectric properties were studied with broadband spectroscopy in a frequency range from 0.1 Hz to 1 MHz in 55 steps designed on a logarithmic scale and a temperature range from 293.15 to 333.15 K with a 5 K step. Optical properties of nanocomposites were measured with UV-VIS spectroscopy at wavelengths from 190 to 1100 nm. The experimental data show that the addition of silicon-dioxide–lignin and glycerine significantly affected the electrical properties of the studied nanocomposites based on polylactide. Permittivity and electrical conductivity show a significant increase with an increasing concentration of nanoparticle filler. The optical properties are also affected by nanofiller and cause an increase in absorbance as the number of silicon-dioxide–lignin nanoparticles increase.

Study of thermal conductivity in two-dimensional Bi2Te3 from micro-Raman spectroscopy

2021 ◽  
Vol 01 ◽  
Author(s):  
Manavendra P. Singh ◽  
Sumarlang Ryntathiang ◽  
Sivarama Krishnan ◽  
Pramoda K. Nayak
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Temperature Coefficient ◽  
Raman Spectra ◽  
Heat Dissipation ◽  
Surface States ◽  
Power Coefficient ◽  
Great Promise ◽  
Temperature Dependent ◽  
Micro Raman Spectroscopy

Background: Topological insulator (TI), Bi2Te3 is a new class of the quantum materials. Having ultralow dissipation surface states, TIs hold great promise toward different potential applications. Micro-Raman spectroscopy is a conventional and non-destructive technique, which has been widely used to characterize the structural and electronic properties of the thermoelectric materials. Objective: To study power dependent and temperature dependent Raman spectra of Bi2Te3 nano flakes on SiO2/Si substrate to estimate the temperature coefficient and thermal conductivity of these flakes for possible application of this material in thermoelectrics. Method: Bi2Te3 flakes of different thicknesses were mechanically exfoliated from high quality bulk Bi2Te3 crystal using scotch tape on 300 nm SiO2/ Si substrates. The power dependent and temperature dependent Raman spectra were acquired with the help of HORIBA LabRAM confocal micro-Raman system in a back scattering geometry. Result: . The observed power dependent and temperature dependent Raman spectra of Bi2Te3 nano flakes follow the same trend as discussed in various literatures. From temperature coefficient and power coefficient values, the in plane thermal conductivity has been estimated, which is found to be in the order of 10 2 W/m-K. The enhancement in the thermal conductivity suggests that the underlying substrate significantly affects the heat dissipation of the Bi2Te3 flake based on the coupling strength with Bi2Te3. Conclusion: This work provides a good platform to understand the role of substrate on the thermal conductivity of exfoliated Bi2Te3 nano flakes and this study can be extended to other substrates.

scholarly journals Diagnosis of Dental Fluorosis Using Micro-Raman Spectroscopy Applying a Principal Component-Linear Discriminant Analysis

2021 ◽  
Vol 18 (20) ◽  
pp. 10572
Author(s):  
Marco Antonio Zepeda-Zepeda ◽  
Michel Picquart ◽  
María Esther Irigoyen-Camacho ◽  
Adriana Marcela Mejía-Gózalez
Keyword(s):  
Raman Spectroscopy ◽  
Discriminant Analysis ◽  
Linear Discriminant Analysis ◽  
Raman Spectra ◽  
Cross Validation ◽  
Dental Fluorosis ◽  
Principal Component ◽  
Control Group ◽  
Linear Discriminant ◽  
Micro Raman Spectroscopy

Dental fluorosis is an irreversible condition caused by excessive fluoride consumption during tooth formation and is considered a public health problem in several world regions. The objective of this study was to evaluate the capability of micro-Raman spectroscopy to classify teeth of different fluorosis severities, applying principal component analysis and linear discriminant analysis (PCA-LDA), and estimate the model cross-validation accuracy. Forty teeth of different fluorosis severities and a control group were analyzed. Ten spectra were captured from each tooth and a total of 400 micro-Raman spectra were acquired in the wavenumber range of 250 to 1200 cm–1, including the bands corresponding to stretching and bending internal vibrational modes n1, n2, n3, and n4 (PO43–). From the analysis of the micro-Raman spectra an increase in B-type carbonate ion substitution into the phosphate site of the hydroxyapatite as fluorosis severity increases was identified. The PCA-LDA model showed a sensitivity and specificity higher than 94% and 93% for the different fluorosis severity groups, respectively. The cross-validation accuracy was higher than 90%. Micro-Raman spectroscopy combined with PCA-LDA provides an adequate tool for the diagnosis of fluorosis severity. This is a non-invasive and non-destructive technique with promising applications in clinical and epidemiological fields.

Micro-Raman Characterization of Arsenic-Implanted Silicon: Interpretation of the Spectra

1999 ◽  
Vol 588 ◽  
Author(s):  
James P. Lavine ◽  
David D. Tuschel
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Room Temperature ◽  
Micro Raman Spectroscopy ◽  
Raman Characterization

AbstractRaman spectra were measured on arsenic-implanted silicon with micro-Raman spectroscopy in the backscattering mode and with macro-Raman spectroscopy. A peak is observed between 505 and 510 cm−1 with 488 and 514.5 nm excitation. This peak and a related peak from the substrate at about 520 cm−1 are seen in selected regions of the implanted samples when the implant dose is above 2 × 1014 As/cm2. These features may be due to a long room temperature anneal, as they are absent in recently prepared samples. Possible explanations for the features are presented.

scholarly journals Effect of Red Light-Emitting Diodes Irradiation on Hemoglobin for Potential Hypertension Treatment Based on Confocal Micro-Raman Spectroscopy

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Xuejun Qiu ◽  
Hanchuan Huang ◽  
Zhitong Huang ◽  
Zhengfei Zhuang ◽  
Zhouyi Guo ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Oxygen Binding ◽  
Dependent Manner ◽  
Light Emitting ◽  
Micro Raman Spectroscopy ◽  
Heme Aggregation ◽  
Led Irradiation

Red light-emitting diodes (LED) were used to irradiate the isolated hypertension hemoglobin (Hb) and Raman spectra difference was recorded using confocal micro-Raman spectroscopy. Differences were observed between the controlled and irradiated Hb by comparing the spectra records. The Raman spectrum at the 1399 cm−1 band decreased following prolonged LED irradiation. The intensity of the 1639 cm−1 band decreased dramatically in the first five minutes and then gradually increased in a time-dependent manner. This observation indicated that LED irradiation increased the ability of oxygen binding in Hb. The appearance of the heme aggregation band at 1399 cm−1, in addition to the oxygen marker band at 1639 cm−1, indicated that, in our study, 30 min of irradiation with 15.0 mW was suitable for inhibiting heme aggregation and enhancing the oxygen-carrying capacity of Hb. Principal component analysis showed a one-to-one relationship between irradiated Hb at different time points and the corresponding Raman spectra. Our approach could be used to analyze the hemoglobin from patients with confocal micro-Raman spectroscopy and is helpful for developing new nondrug hypertension therapy.

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