Glasses optical characterization

TaF has been characterized by ir, Raman, x-ray diffraction, and mass spectrometry (3,11,12). TaF has been used as a superacid catalyst for the conversion of CH to gasoline-range hydrocarbons (qv) (12) in the manufacture of fluoride glass and fluoride glass optical fiber preforms (13), and incorporated in semiconductor devices (14). TaF is also a catalyst for the Hquid-phase addition of HF to polychlorinated ethenes (15). The chemistry of TaF has been reviewed (1,16—19). Total commercial production for TaF is thought to be no more than a few hundred kilograms aimuaHy. 

The systematic synthesis of non amphiphilic l.c.-side chain polymers and detailed physico-chemical investigations are discussed. The phase behavior and structure ofnematic, cholesteric and smectic polymers are described. Their optical properties and the state of order of cholesteric and nematic polymers are analysed in comparison to conventional low molar mass liquid crystals. The phase transition into the glassy state and optical characterization of the anisotropic glasses having liquid crystalline structures are examined. 

Similar methods have been used to prepare CdS NCs in optical quality borosilicate glasses." Nonlinear optical characterization of one composite sample with particle sizes ranging from 2.5-5.5nm yielded a range for of 10 -10 esu. Optical gain measurements of a similar material afforded a value of 33 cm at room temperature. At 11 K, maximum gain values reached 200 cm , and like the optical nonlinearities, these values were also dependent on NC concentration. ... 

Another approach involved the use of a carbonate membrane bonded to SU8 channels with a glass layer used to seal the device [29]. The system used a stacked approach with a dialysis membrane sandwiched between an SU8 perfusion channel and a poly(dimethylsiloxane) flow channel (Figure 48.4). Bonding the membrane reduced the chance of leakage and resulted in a more robust device. A fluorescent dye and glucose solution were used for optical characterization of the system. A eommercially available glucose sensor was used to determine the concentration of glucose in the dialysate. A recovery of 80% was obtained at flow rate of 1.5 tiL/min. 

Commercially available microscope glass slides were used as substrates for optical characterization of the PPV thin films. For the light emitting devices, glass substrates patterned with 2 mm wide and about 2000 A thick lines of indium tin oxide (ITO) were used as transparent electrodes. Evaporated aluminum was used as the top electrode material in all devices. 

Germany, produced two types of this glass-ceramic, characterized by different optical transmission (Pannhorst 1992 and Nass et al., 1995). The products are called Ceran Color and Ceran Hightrans . 

Electrical and optical characterization. A four probe apparatus (JANDEL JA 010) was used for aelectric current was provided by a KEITHLEY 224 current source and a KEITHLEY 617 electrometer was used to measure the voltage. Gdc measurements were carried out on free standing films or deposits. Film thicknesses were determined using a Dektak ST surfiice profiler. In order to get reliable values ofconductivity surface resistance R of deposits on glass slides were measured as a function of the thickness of the film (Figure 9). Conductivity was then given by the slope of the curve of the inverse of R as a... 

Casalboni M., De Matteis F., Prosposito P., Pizzoferrato R., Vinattieri A. Optical characterization of IR active eomposite glasses. Opt. Mater. 2001 18 285-293 Casalboni M., De Matteis F., Proposito P., Quatels A., SarcineUy F. Fluorescence efficiency of four infrared polymethine dyes. Chem. Phys. Lett. 2003 373 372-378 Drexhage K.N. Structure and propafies of laso" dyes. In Topics in Applied Physics. Dye Lasers, Schafer F.P. ed., 1990 pp. 155-186... 

Phosphate glasses find wide applications as laser media and optical windows, and more recently as bioactive materials. Phosphate glasses are characterized by the chain or network structures formed by [PO4] tetrahedrons linked through bridging oxygen ions [62], Compared to [Si04] tetrahedron, there exist a terminal double bond FM3... 

Formulas for Optical Characterization The characterization of optical glasses through the refractive index and Abbe value alone is insufficient for high-quality optical systems. A more accurate description of the properties of a glass can be achieved with the aid of the relative partial dispersion. 

SiO2 50PbF2 glass-ceramics doped with 4 % (mol) ErF3 or 1 % (mol) EUF3 can also be synthesized [28]. Some optical characterizations evidence the segregation of Er (or Eu ) inside fi-PhV nanocrystallites. 

Specific applications of DIRLD spectroscopy are presented for several polymer systems to demonstrate the types of information obtainable from this powerful rheo-optical characterization technique. A DIRLD study of atactic polystyrene revealed the existence of highly localized motion of various molecular constituents induced by a macroscopic dynamic strain.It was discovered the rate of reorientational motion of the polystyrene backbone differs considerably from that of the phenyl side groups. The reorientation direction of the phenyl side groups changes dramatically as the temperature of the system is raised above the glass transition temperature. This result may be interpreted as the onset of a new submolecular... 

Most Kaminsky catalysts contain only one type of active center. They produce ethylene—a-olefin copolymers with uniform compositional distributions and quite narrow MWDs which, at their limit, can be characterized by M.Jratios of about 2.0 and MFR of about 15. These features of the catalysts determine their first appHcations in the specialty resin area, to be used in the synthesis of either uniformly branched VLDPE resins or completely amorphous PE plastomers. Kaminsky catalysts have been gradually replacing Ziegler catalysts in the manufacture of certain commodity LLDPE products. They also faciUtate the copolymerization of ethylene with cycHc dienes such as cyclopentene and norhornene (33,34). These copolymers are compositionaHy uniform and can be used as LLDPE resins with special properties. Ethylene—norhornene copolymers are resistant to chemicals and heat, have high glass transitions, and very high transparency which makes them suitable for polymer optical fibers (34). 

The potentiostatic electrodeposition of iron selenide thin films has been reported recently in aqueous baths of ferric chloride (FeCb) and Se02 onto stainless steel and fluorine-doped TO-glass substrates [193], The films were characterized as polycrystalline and rich in iron, containing in particular a monoclinic FesSea phase. Optical absorption studies showed the presence of direct transition with band gap energy of 1.23 eV. 

The NIST material SRM 1866a consists of a set of three common bulk mine-grade asbestos materials chrysotile, amosite and crocidolite, and one glass filter sample. SRM 1867 consists of a set of three imcommon mine-grade asbestos materials antophyllite, tremolite and actinohte. The optical properties of SRMs 1866a and 1867 have been characterized so that they may serve as primary calibration standards for the identification of asbestos types in building materials. 

The radii of both orifices can be either on a micrometer or a submicrometer scale. If the device is micrometer-sized, it can be characterized by optical microscopy. The purposes of electrochemical characterization of a dual pipette are to determine the effective radii and to check that each of two barrels can be independently polarized. The radius of each orifice can be evaluated from an IT voltammogram obtained at one pipette while the second one is disconnected. After the outer surface of glass is silanized, the diffusion-limiting current to each water-filled barrel follows Eq. (1). The effective radius values calculated from that equation for both halves of the d-pipette must be close to the values found from optical microscopy. 

Transmission electron microscopy (TEM) is a powerful and mature microstructural characterization technique. The principles and applications of TEM have been described in many books [16 20]. The image formation in TEM is similar to that in optical microscopy, but the resolution of TEM is far superior to that of an optical microscope due to the enormous differences in the wavelengths of the sources used in these two microscopes. Today, most TEMs can be routinely operated at a resolution better than 0.2 nm, which provides the desired microstructural information about ultrathin layers and their interfaces in OLEDs. Electron beams can be focused to nanometer size, so nanochemical analysis of materials can be performed [21]. These unique abilities to provide structural and chemical information down to atomic-nanometer dimensions make it an indispensable technique in OLED development. However, TEM specimens need to be very thin to make them transparent to electrons. This is one of the most formidable obstacles in using TEM in this field. Current versions of OLEDs are composed of hard glass substrates, soft organic materials, and metal layers. Conventional TEM sample preparation techniques are no longer suitable for these samples [22-24], Recently, these difficulties have been overcome by using the advanced dual beam (DB) microscopy technique, which will be discussed later. 

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