Abstract: A spectroscopic method is disclosed for detecting and measuring contaminants in fluids such as water or oil, where the hydrophilicity of the contaminant is substantially different from that of the contaminated fluid. Good calibrations can be obtained at very low concentrations using infrared spectroscopy with ATR crystals that have not been additionally coated or otherwise modified.

Abstract: An accessory for an FTIR spectrometer comprises fiber-optic cables connected to a framework within which two mirrors are housed. The mirrors, which are preferably off-axis parabolas, are positionable with respect to each other and with respect to the ends of the fiber-optic cables. The beam from the first cable is reflected by the first mirror onto a sample surface at or near the grazing angle, after which it is captured by the second mirror and focused onto the end of the return cable which transmits it back to the spectrometer. Very thin films and coatings can be spectroscopically detected and characterized using the accessory.

Abstract: A mid-infrared spectroscopic probe attached to a fiber-optic cable comprises an optically transparent, heat-insulating crystal which is placed between the ATR crystal and the end of the fiber-optic cable so as to provide optical coupling from the cable to the ATR crystal while protecting the fiber-optic assembly inside the cable from excessive heat when the probe is used in high-temperature sample streams. The ATR crystal is tapered outwards towards the sampling end to ensure that pressure from the sample stream, e.g., in a plastics extruder, does not displace the crystal, but rather forces it into tighter contact with the seal in the probe head.

Abstract: A fiber-optic spectroscopic probe for use with an FTIR spectrometer comprises two or more types of optical fibers made from materials with overlapping transmissions in the infrared region of the spectrum. The fiber materials are chosen so that so that any regions of low or zero transmission in their respective transmission windows, arising from impurities or defects in the material, occur in different spectral regions, thus ensuring that the probe is able to transmit across the entire transmission window without exhibiting the characteristic "blind spots" that are observed using probes comprising a single type of optical fiber.

Abstract: A fiber-optic spectroscopic probe for use with a Fourier Transform Infrared (FTIR) spectrometer for sensing the absorption of infrared energy by a sample has a shaft containing a fiber optic bundle which terminates proximate the end of the shaft for transmitting and receiving infrared energy from the sample being measured by a measuring head. The shaft has means for detachably attaching interchangeable measuring heads for measuring attenuated total reflectance, diffuse or specular reflectance of the sample, or for measuring the infrared energy transmitted through the sample. The interchangeable heads are coupled to the shaft without the use of additional optics or mechanical positioning devices. The shaft assembly may include a cooling jacket for measuring samples at elevated temperatures. Having different, interchangeable spectral sampling heads makes it possible to obtain quantitative spectral data from a wide range of samples in varying states of agglomeration and homogeneity using a single device.

Abstract: A method of making a polyimide coated heavy metal fluorinated fiber includes the steps of drawing an optical fiber through a low-temperature curing polyimide solution to form a polyimide coating which cures in a range of about 200.degree. and 390.degree. C. A low curing temperature enables a low temperature profile to be used for curing the coating. The low-temperature curing conditions provide a maximum fiber exposure temperature above the glass transition temperature of the fiber but minimize crystallization of the fiber during curing. The method is also applicable to chalcogenide fibers which carry optical signals in the infrared region.

Abstract: A method of making a polyimide coated heavy metal fluorinated fiber includes the steps of drawing an optical fiber through a low-temperature curing polyimide solution to form a polyimide coating which cures in a range of about 200.degree. and 390.degree. C. A low curing temperature enables a low temperature profile to be used for curing the coating. The low-temperature curing conditions provide a maximum fiber exposure temperature above the glass transition temperature of the fiber but minimize crystallization of the fiber during curing. The method is also applicable to chalcogenide fibers which carry optical signals in the infrared region.

Abstract: A method for producing a thin film of a ferroelectric perovskite material having the steps of providing a first substrate; depositing a first layer of a sol-gel perovskite precursor material wherein the crystallization of this precursor material to the pervoskite phase is insensitive to the first substrate; depositing a second layer of a sol-gel perovskite precursor material wherein the crystallization is sensitive to the first substrate; and heat-treating the deposited layers to form ferroelectric perovskites. A heat treatment step to form perovskites may optionally follow the deposition of the first layer. The first layer of sol-gel perovskite precursor material is selected to produce a perovskite upon heat treatment of: lead titanate (PbTiO.sub.3), or strontium titanate (SrTiO.sub.3). The second layer of sol-gel perovskite precursor material is selected to produce a perovskite upon heat treatment of: lead zirconate titanate (Pb(Zr,Ti)O.sub.3), lead zirconate (PbZrO.sub.

Abstract: The invention is directed to a probe operative in the infrared region of the electromagnetic spectrum for in situ sensing of the absorption of IR energy in a sample. The probe comprises an attenuated total reflection (ATR) element having an input end and an output end for respectively receiving IR and transmitting attenuated IR. The ATR element has wall portions disposed about a central or long axis thereof for reflecting IR energy transverse to the central axis. A bundle of infrared transmitting fibers is located at the input end of the ATR element for transmitting and receiving IR energy into and out of the element. The fibers have end faces proximate the ATR element lying in a plane perpendicular to the central axis.

Abstract: Process for producing high purity aluminum nitride powder by reacting aluminum sulfide with gaseous ammonia at an intermediate temperature (about 700.degree. C.) and holding at that temperature until an intermediate product (Al.sub.x N.sub.y S.sub.z) is formed where x, y, and z are integers; then further heating to a temperature above 1100.degree. C. and reacting with gaseous ammonia. A high purity, low oxygen containing, free flowing powder is produced. A posttreatment using a carbon source such as graphite further reduces the oxygen content. The oxygen content can be further reduced by reacting the aluminum nitride formed with carbon at about 1600.degree. C.

Abstract: A process for curing and densifying a sol-gel derived inorganic thin film at lower temperatures (between 10.degree. C. and 400.degree. C.) by applying the films to a substrate, drying the film at a low temperature, exposing the film to a low pressure plasma. The film may be an oxide (e.g. SiO.sub.2), nitride (e.g. Si.sub.3 N.sub.4), oxynitride (e.g. SiO.sub.x N.sub.y) or sulfide (e.g. GeS.sub.2).