Molecular Sieve Based Chemical Sensors

1994 ◽  
Vol 351 ◽  
Author(s):  
Laura J. Sottile ◽  
Kenneth J. Balkus ◽  
Scott J. Riley ◽  
Bruce E. Gnade
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Titanium Nitride ◽  
Hydrothermal Treatment ◽  
Chemical Sensors ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Aluminum Phosphate ◽  
Shape Selectivity ◽  
Target Molecules

ABSTRACTBy virtue of their shape selectivity and stability, molecular sieves are ideal components for discriminating chemical sensors. In this paper we report the preparation of capacitance type sensors based on aluminum phosphate molecular sieves. Thin films of the molecular sieves AlPO4-5, A1PO 4-H3 and AlPO4-H1, which cover a range of pore dimensions, were deposited on titanium nitride coated silicon wafers by laser ablation. A subsequent hydrothermal treatment followed by a Pd/Au coating and the application of standard photoresist/masking techniques were used to generate the capacitors. The molecular sieves exhibit significant changes in capacitance upon exposure to target molecules, including CO2, CO, N2, H2O and toluene.

Molecular Sieve Thin Films via Laser Ablation

1994 ◽  
Vol 351 ◽  
Author(s):  
Kenneth J. Balkus ◽  
Scott J. Riley ◽  
Bruce E. Gnade
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Film Formation ◽  
Aluminum Phosphate ◽  
Effective Technique ◽  
Solid Films ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

ABSTRACTLaser ablation has become widely recognized as an effective technique for the preparation of thin solid films. We have employed an excimer laser (KrF, 248 nm) to deposit well dispersed thin films of aluminum phosphate molecular sieves on a titanium nitride substrate. Results for the ablation of AIPO4-5, AIPO4-H3 and AIPO4-H1 molecular sieve targets are presented. The laser power and repetition rate as well as substrate distance and temperature affect the thin film formation. A subsequent hydrothermal post treatment of the ablated films was found to enhance the surface crystallinity. The molecular sieve thin films were characterized by XRD, SEM, XRF, and FT-IR spectroscopy.

Pulsed Laser Ablation of Low-Density Nanoporous Metal Oxides

1998 ◽  
Vol 526 ◽  
Author(s):  
Mary E. Gimon-Kinsel ◽  
Trinidad Muñoz ◽  
Kenneth J. Balkus
Keyword(s):  
Electron Microscopy ◽  
Laser Ablation ◽  
Metal Oxides ◽  
Hydrothermal Treatment ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Low Density ◽  
Mcm 41

AbstractPulsed laser ablation has been employed to generate thin films of low density metal oxides, including nanoporous molecular sieves. An excimer laser (KrF*, 248 nm) was used to deposit molecular sieve films onto a variety of substrates including polished silicon, platinum, tantalum, titanium nitride, glass, indium-doped tin oxide, copper and Mylar. Recent results for the deposition of microporous UTD-1 and FeAPO-5 as well as mesoporous aluminosilicate MCM-41 and Nb-TMSI molecular sieve films are presented. The order (crystallinity) of the laser deposited films has been shown to be enhanced by a brief post hydrothermal treatment. A vapor phase treatment of the laser deposited FeAPO-5 films allows for increases in film crystallinity without an increase in film thickness. Hydrothermal treatment of laser deposited Nb-TMSI results in “worm hole” pore motif which is new for this composition. Silicate based molecular sieves such as UTD-1 and aluminosilicate MCM-41 require a UV-absorbing guest molecule for laser ablation giving rise to a phenomenon referred to as guest assisted laser ablation (GALA). The molecular sieve films were characterized by x-ray diffraction, scanning electron microscopy and transmission electron microscopy.

Molecular Sieve Based Chemical Sensors

1994 ◽  
Vol 371 ◽  
Author(s):  
Kenneth J. Balkus ◽  
Laura J. Sottile ◽  
Hoan Nguyen ◽  
Scott J. Riley ◽  
Bruce E. Gnade
Keyword(s):  
Chemical Sensors ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Chemical Sensor ◽  
Selective Adsorption ◽  
Capacitance Measurements ◽  
Saw Devices ◽  
Signature Change ◽  
Shape Selective ◽  
Target Molecules

AbstractMolecular sieves, are attractive materials for discriminating chemical sensors. These microporous metal oxides offer shape selective adsorption as well as chemical and thermal stability. Molecular sieves have shown promise in SAW devices, however, these sensors rely only on a weight change upon adsorption of target molecules. We have developed a molecular sieve based capacitance type chemical sensor. Such a device should discriminate between molecules of similar size and shape because the signature change depends on the polarity of the adsorbate which in turn affects the dielectric properties of the molecular sieve. In this paper we describe the deposition of AIPO4 and MeAPO molecular sieve thin films on titanium nitride coated silicon wafers by laser ablation. A subsequent hydrothermal treatment followed by a Pd/Au coating and standard microlithography techniques generate the capacitors. The results for capacitance measurements in the presence of CO2, CO, NO, N2, O2, H2O and toluene indicate clear differences in selectivity between small, medium and large pore molecular sieves.

The Preparation of Partially Oriented Zeolite Thin Films via Pulsed Laser Ablation

2002 ◽  
Vol 752 ◽  
Author(s):  
Zhongsheng Deng ◽  
Thomas J. Pisklak ◽  
Kenneth J. Balkus
Keyword(s):  
Thin Films ◽  
Stainless Steel ◽  
Laser Ablation ◽  
Pulsed Laser Deposition ◽  
Hydrothermal Treatment ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Laser Deposition ◽  
Treatment Results ◽  
Stainless Steel Foil

ABSTRACTThin films of zeolites including silicalite-1, mordenite and UTD-18 have been prepared on stainless steel foil via pulsed laser deposition (PLD). Laser ablation of as-synthesized zeolite targets onto stainless steel foil followed by a post hydrothermal treatment results in partially oriented zeolite thin films. SEM, XRD were used to characterize the zeolite thin films. Preliminary results for multilayercoatings of different zeolites will also be presented.

Effect of the plasma parameters on the properties of titanium nitride thin films grown by laser ablation

2005 ◽  
Vol 81 (6) ◽  
pp. 1221-1226 ◽  
Author(s):  
L. Escobar-Alarcón ◽  
E. Camps ◽  
M.A. Castro ◽  
S. Muhl ◽  
J.A. Mejia-Hernandez
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Titanium Nitride ◽  
Plasma Parameters

Titanium nitride thin films deposited by reactive pulsed-laser ablation in RF plasma

2002 ◽  
Vol 151-152 ◽  
pp. 316-319 ◽  
Author(s):  
A. Giardini ◽  
V. Marotta ◽  
S. Orlando ◽  
G.P. Parisi
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Titanium Nitride ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Rf Plasma

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

GLANCING INCIDENCE X-RAY STUDIES OF TITANIUM NITRIDE THIN FILMS USING A NEW MULTIPURPOSE LABORATORY SPECTROMETER

1989 ◽  
Vol 50 (C7) ◽  
pp. C7-169-C7-173
Author(s):  
R.C BUSCHERT ◽  
P. N. GIBSON ◽  
W. GISSLER ◽  
J. HAUPT ◽  
T. A. CRABB
Keyword(s):  
Thin Films ◽  
Titanium Nitride ◽  
X Ray

Plasmonic properties of titanium nitride thin films prepared by ion beam assisted deposition

2016 ◽  
Vol 185 ◽  
pp. 295-298 ◽  
Author(s):  
Lin-Ao Zhang ◽  
Hao-Nan Liu ◽  
Xiao-Xia Suo ◽  
Shuo Tong ◽  
Ying-Lan Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Titanium Nitride ◽  
Ion Beam ◽  
Ion Beam Assisted Deposition
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