Introduction
X-ray diffraction is an analytical technique looking at X-ray scattering from crystalline materials. Each material produces a unique X-ray "fingerprint" of X-ray intensity versus scattering angle that is characteristic of its crystalline atomic structure. Qualitative analysis is possible by comparing the XRD pattern of an unknown material to a library of known patterns. The three-dimensional structure of non-amorphous materials is defined by regular, repeating planes of atoms that form a crystal lattice.
Working
When a focused X-ray beam interacts with these planes of atoms, part of the beam is transmitted, part is absorbed by the sample, part is refracted and scattered, and part is diffracted. When an X-ray beam hits a sample and is diffracted, we can measure the distances between the planes of the atoms that constitute the sample by applying Bragg's Law. Bragg's Law is nλ=2d sinθ, where the integer n is the order of the diffracted beam, λ is the wavelength of the incident X-ray beam, d is the distance between adjacent planes of atoms (the d-spacings), and θ is the angle of incidence of the X-ray beam. Since we know λ and we can measure θ we can calculate the d-spacings. The characteristic set of d-spacings and theirs intensity generated in a typical X-ray scan provides a unique "fingerprint" of the phases present in the sample. When properly interpreted, by comparison with standard reference patterns and measurements, this "fingerprint" allows for identification of the material. Presence of an amorphous material in the sample can be determined by occurrence of specific wide halo on diffraction pattern.
Software
Diffrac Plus software for Bruker AXS diffractometer D8 Advance allows carrying ou...
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...pplied to phase quantification only if structures of all phases are known. At the same time still a direct method, an internal standard method and relative intensity ratio (RIR) method are used. It should be noted that each of the available methods has its intrinsic limitation, so that final choice should be made based on specific task and material to be analysed.
APPLICATIONS
• Rocking curves:
Composition, thickness (300-10000 Å), mismatch
• Reciprocal lattice mapping:
Composition, thickness (at least 500 Å), mismatch
Mosacity and defects profile
• Reflectivity measurements:
Composition, thickness and interface roughness, Layer thickness range of 50-1500 Å (thin layer measurement)
• Pole figures:
Finding layer composition, orientation with respect to substrate
• quality samples) and phase analysis
The complete experimental procedure is available in the General Chemistry Laboratory Manual for CSU Bakersfield, CHEM 213, pages 20-22, 24-25. Experimental data are recorded on the attached data pages.
Mixed melting point was used to confirm the identity of the product. The smaller the range, the more pure the substance. When the two substances are mixed; the melting point should be the same melting range as the as the melting range obtained after filtering. If the mixed melting point is lower one taken from the crystals, then the two substances are different.
Physical Chemistry Laboratory Manual, Physical Chemistry Laboratory, Department of Chemistry, University of Kentucky, Spring 2006.
The color that was chose to be shined through the sample was purple. The spectrophotometer was set at a wavelength of 400nm to represent the purple color. It was zeroed using the blank meaning the spectrophotometer read zero as absorbance amount. The blank consisted of 5mL of water and 2.5 mL AVM and it was placed in cuvette. A solution with a known concentration of 2.0x10-4 M was used in the spectrometer. For this solution, 5 mL of the solution with 2.5 mL of AMV was placed in the cuvette. The cuvette was placed inside of spectrophotometer and the amount of absorbance was recorded. This procedure that involves a solution with a known concentration was repeated for the concentrations:1.0x10-4 M,5.0x10-5 M,2.0x10-5M, and1.0x10-5M.A unknown solution absorbance was measured by putting 5 mL of unknown solution with 2.5 mL AMV in a cuvette. The cuvette was placed in the spectrophotometer and the amount of absorbance was recorded. The procedure that deals with the unknown solution was repeated 2 more times with the same solution and the same amount of solution and AMV. The average of the three unknown solution was calculated and the concentration of the unknown solution was
The nano-thermal analysis method is capable of studying the specific regions of a sample irrespective of its composition. In a multi-component sample, the analysis methods make it possible for the researchers to distinguish between the different components and identify the different characteristics found in each of the sample (Craig, 2002). During the analysis of any sample, the nano-thermal method does not necessarily require the physical alteration of the sample. In its place, it is capable of analyzing any sample through surface studies.
One of the first people to study the xenoliths at El Joyazo was Zeck (1970); Zeck hypothesised that the xenoliths and dacitic lava of El Joyazo were derived syn-genetically from a semi-pelitic rock through anatexis. The protolith rock was thought to be separated into anatectic restites, represented by Al-rich xenoliths, and anatectic melt, represented by the dacitic lavas. The xenoliths were classified into three types: (1) almandine-biotite-sillimanite gneiss, (2) quartz-cordierite gneiss and (3) spinel-cordierite rock. Types 1 & 2 were interpreted as restite material as their structure corresponded to that of migmatitic restite, and type 3 as re-crystallised restite. It was suggested that this re-crystallisation would have taken place after that anatexis that produced types 1 & 2. Zeck described the lava, based on chemical composition, as an almandine bearing biotite-cordierite-labradorite rhyodacite. The xenoliths were described as well rounded fragments up to 40cm in diameter. The xenoliths were said to show a well developed foliation defined by biotite and sillimanite, with the exception of the spinel-cordierite rock, which exhibited a granoblastic texture. It was also noted that quartz is almost completely absent from these rocks with the exception of small, rare armoured relicts.
Infra-red spectroscopy was first used in 1950's by Wilbur Kaye. He designed a machine that tested the near-infrared spectrum and was able to provide the theory to describe the results. There have been many advances in the field of IR Spec, the most applicable was the application of Fourier Transformations. ”The Fourier Transform is a tool that breaks a waveform (a function or signal) into an alternate representation, characterized by sine an...
X-rays have benefited the medical field for over a hundred years (Radiology). Wilhelm Conrad Roentgen, a German Physics Professor, discovered the x-ray (Career as a Radiologic Technician, Radiography, Ultrasound X-ray Technician). Dartmouth College in New Hampshire performed the first procedure on February 3, 1896 (Radiology). Radiologic
An excerpt from Hebrew 12:14 in the bible states, “Strive for peace with everyone, and for the holiness without which no one will see the Lord.” In other words, one must make every effort to pursue peace in others and to be holy; no one will meet the Lord without holiness. Being able to understand the holiness in others means to be able to perceive goodness in everyone, no matter their history, ethnicity, or sins they may have committed.
Spectroscopy Spectroscopy is the study of energy levels in atoms or molecules, using absorbed or emitted electromagnetic radiation. There are many categories of spectroscopy eg. Atomic and infrared spectroscopy, which have numerous uses and are essential in the world of science. When investigating spectroscopy four parameters have to be considered; spectral range, spectral bandwidth, spectral sampling and signal-to-noise ratio, as they describe the capability of a spectrometer. In the world of spectroscopy there are many employment and educational opportunities as the interest in spectroscopy and related products is increasing.
Since the discovery of X-rays in 1895 by Wilhelm Röntgen, radiology has contributed substantially to the medical field. Today, X-rays are still considered to be one of the most important tools in diagnostic imaging. Further advancements in imaging have combined the use of nuclear science and radiography and is known as nuclear medicine.
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
In order to learn how glass fractures, we must first learn the composition of glass and the different types of glass. Glass is a hard, brittle, amorphous substance composed of sand (silicon oxides) mixed with various metal oxides. When sand is mixed with other metal oxides, melted at high temperatures, and then cooled to a rigid condition without crystallization, the product is glass (Saferstein, 2010). Glass can come in many different forms all of which can range from very brittle glass to bullet proof glass; the stronger the glass, the more ingredients are required and the more complex the process is.
An oscilloscope is an electronic test instrument that is used to observe an electronic signal, typically voltage, as a function of time. In other words, it is a voltage versus time plotter. Oscilloscopes come in two basic types, analogue or digital, and support various features and functions useful for measuring and testing electronic circuits. An oscilloscope is a key piece of test equipment for any electronics designer.
In summary, the rate of cooling from the austenite phase is the main determinant of final structure and properties.