TITLE

Improved pyroelectric detectors for single crystal adsorption calorimetry from 100 to 350 K

AUTHOR(S)
Lew, Wanda; Lytken, Ole; Farmer, Jason A.; Crowe, Matthew C.; Campbell, Charles T.
PUB. DATE
February 2010
SOURCE
Review of Scientific Instruments;Feb2010, Vol. 81 Issue 2, p024102
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The adsorption of atoms and molecules on single crystal surfaces allows one to produce well-characterized atomic, molecular, or dissociated adsorbates. Microcalorimetric measurement of the resulting adsorption energies, i.e., single crystal adsorption calorimetry, allows determination of the standard enthalpies of formation of these adsorbates. Methods are described for making an improved heat detector for such measurements, which greatly improves the signal-to-noise ratio, particularly at low temperatures (down to 100 K). The heat detector is an adaptation of a previously introduced design, based on a metallized pyroelectric polymer (β-polyvinylidene fluoride), which is pressed against the back of a single crystal during measurement but removed during sample preparation and annealing. The improvement is achieved by selectively etching the metal coating of the polymer, thus reducing the pyro- and piezoelectric noise from all nonessential regions of the polymer. We, furthermore, describe how to achieve a better thermal contact between the sample and the pyroelectric polymer, without increasing the thermal mass of the detector, resulting in significantly improved sensitivities for both 1 and 127 μm thick samples. The result is a detector which, using 1 μm samples, is ∼40 times more sensitive at 100 K than the traditional polymer-based detector, showing a pulse-to-pulse standard deviation in the heat of adsorption of just 1.3 kJ/mol with gas pulses containing only 1.1% of a monolayer onto Pt(111), for which 1 ML (monolayer) is 1.5×1015 species/cm2. For measurements at 300 K, where especially pyroelectric noise is likely of less concern, the new design improves the sensitivity 3.6-fold compared to the traditional detector. These improvements are furthermore used to propose a new detector design that is able to measure heats of adsorption on samples as thick as 127 μm with reasonable sensitivity.
ACCESSION #
48352595

 

Related Articles

  • Pyroelectric infrared sensor-based thermometer for monitoring indoor objects. Tsai, C. F.; Young, M. S. // Review of Scientific Instruments;Dec2003, Vol. 74 Issue 12, p5267 

    This article describes a system for measuring temperature by monitoring an object’s radiation in the infrared spectrum. Using a measuring device by passing through a data acquisition interface, a long-term observation of the temperature variance of objects on a personal computer by the...

  • Measurement of nanoparticle temperature in a (CO2) N cluster beam using SF6 molecules as tiny probe thermometers. Makarov, G. N.; Petin, A. N. // Journal of Experimental & Theoretical Physics;Apr2010, Vol. 110 Issue 4, p568 

    A temperature measurement technique using SF6 molecules as tiny probe thermometers is described, and results are presented, for large (CO2) N van der Waals clusters (with N ≥ 102) in a cluster beam. The SF6 molecules captured by (CO2) N clusters in crossed cluster and molecular beams...

  • An introduction to ACOUSTIC THERMOMETRY. Williams, Jim; Sanchez-Felipe, Omar // EDN;4/21/2011, Vol. 56 Issue 8, p28 

    The article presents a discussion of acoustic thermometry, defined as a technique that employs a transit time of sound in a medium in order to get the measurement of a temperature. Demonstration of such thermometer involves choosing a sonic transducer and what is called a dimensionally stable...

  • Note: Multi-pass Thomson scattering measurement on the TST-2 spherical tokamak. Togashi, H.; Ejiri, A.; Hiratsuka, J.; Nakamura, K.; Takase, Y.; Yamaguchi, T.; Furui, H.; Imamura, K.; Inada, T.; Kakuda, H.; Nakanishi, A.; Oosako, T.; Shinya, T.; Sonehara, M.; Tsuda, S.; Tsujii, N.; Wakatsuki, T.; Hasegawa, M.; Nagashima, Y.; Narihara, K. // Review of Scientific Instruments;2014, Vol. 85 Issue 5, p1 

    In multi-pass Thomson scattering (TS) scheme, a laser pulse makes multiple round trips through the plasma, and the effective laser energy is enhanced, and we can increase the signal-to-noise ratio as a result. We have developed a coaxial optical cavity in which a laser pulse is confined, and we...

  • Simultaneous CO concentration and temperature measurements using tunable diode laser absorption spectroscopy near 2.3 μm. Sane, Anup; Satija, Aman; Lucht, Robert; Gore, Jay // Applied Physics B: Lasers & Optics;Oct2014, Vol. 117 Issue 1, p7 

    Simultaneous measurements of carbon monoxide (CO) mole fraction and temperature using tunable diode laser absorption spectroscopy (TDLAS) near 2.3 μm are reported. The measurement method uses ro-vibrational transitions [R(27): v″ = 1 → v′ = 3] and [R(6): v″ = 0...

  • Thomson scattering diagnostic upgrade on DIII-D. Ponce-Marquez, D. M.; Bray, B. D.; Deterly, T. M.; Liu, C.; Eldon, D. // Review of Scientific Instruments;Oct2010, Vol. 81 Issue 10, p10D525 

    The DIII-D Thomson scattering system has been upgraded. A new data acquisition hardware was installed, adding the capacity for additional spatial channels and longer acquisition times for temperature and density measurements. Detector modules were replaced with faster transimpedance circuitry,...

  • Error Minimization Algorithm Using Barycentric Coordinates for Wireless Positioning Systems. Joonseong Gim; Jong-Kyun Hong; Sang-Sun Lee // Applied Mathematics & Information Sciences;Sep2013, Vol. 7 Issue 5, p1783 

    This paper presents Barycentric Coordinates using Closed-Points (BCCP) algorithm to minimize positioning error occurred by AP arrangement form. Triangular AP arrangement form and straight line AP arrangement form were used to include measurement error and conduct simulation in which the...

  • Pyroelectric anemometers: Experimental geometric considerations. Frederick, J. R.; Zemel, J. N.; Goldfine, N. // Journal of Applied Physics;6/1/1985, Vol. 57 Issue 11, p4936 

    Presents a study which examined the role of geometric factors in the operation of a modified design of a pyroelectric anemometer (PA). Structure and properties of PA; Experimental procedures; Results and discussion.

  • Characterization of pyroelectric detectors between 170 and 300 K using the photopyroelectric technique. Bentefour, E. H.; Glorieux, C.; Chirtoc, M.; Thoen, J. // Review of Scientific Instruments;Jan2003, Vol. 74 Issue 1, p811 

    In this article, we perform a full characterization of the thermal properties of photopyroelectric detectors in a wide temperature range. Within the experimental uncertainties, the results on lithium tantalate are consistent with results from literature. The thermal properties of polyvinilydene...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics