Mark R. De Guire

Case Western Reserve University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

A. H. Heuer

Case Western Reserve University

Chaim N. Sukenik

Bar-Ilan University

Fritz Aldinger

University of Stuttgart

Hyunjung Shin

Sungkyunkwan University

T. P. Niesen

National Renewable Energy Laboratory

G. Kalonji

Hong Kong Polytechnic University

Uma Sampathkumaran

InnoSense (United States)

Monika Agarwal

Indian Institute of Technology Delhi

Joachim Bill

University of Stuttgart

Narottam P. Bansal

Glenn Research Center

Cooperative Institutions

Case Western Reserve University

State University of New York

Rensselaer Polytechnic Institute

American Ceramic Society

Centre National de la Recherche Scientifique

Max Planck Society

Glenn Research Center

Argonne National Laboratory

Massachusetts Institute of Technology

University of California, Berkeley

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

ChemInform Abstract: Superconducting Glass‐Ceramics in the Bi‐Sr‐Ca‐Cu‐O System.

ChemInform (1990)

Mark R. De Guire Narottam P. Bansal C. J. Kim

Abstract The crystallization behavior during reheating of Bi1.5SrCaCu2Oz (prepared in the glassy state by rapid quenching from the melt) is studied by DTA, XRD, SEM, and resistivity measurements.

Glass-ceramic

10.1002/chin.199033012

Cite

Citations (0)

Ultrasonic evaluation of oxidation and reduction effects on the elastic behavior and global microstructure of YBa2Cu3O7-x

Don J. Roth Mark R. De Guire Leonard E. Dolhert

Ultrasonic velocity measurement techniques were used to evaluate the effects of oxidation and reduction on the elastic properties, global microstructure and oxygen content of the YBa2Cu3O(7-x) ceramic superconductor for samples ranging from 70 to 90 pct. of theoretical density. Bulk density, velocity, and elastic modulus generally increased with increasing oxygen content upon oxidation, and this behavior was reversible. Velocity image patterns were similar after oxidation and reduction treatments for a 90 pct. dense sample, although the velocity value at any given point on the sample was changed following the treatments. The unchanging pattern correlated with destructive measurements showing that the spatial pore distribution (fraction and size) was not measurably altered after the treatments. Changes in superconducting behavior, crystal structure, and grain structure were observed consistent with changes in oxygen content.

Source

Cite

Citations (0)

Pyrolysis of self-assembled organic monolayers on oxide substrates

Journal of materials research/Pratt's guide to venture capital sources (1999)

Hyunjung Shin Yuhu Wang Uma Sampathkumaran Mark R. De Guire A. H. Heuer

Thermogravimetric analysis

Octadecyltrichlorosilane

Silicon dioxide

Titanium Dioxide

10.1557/jmr.1999.0286

Cite

Citations (24)

Long‐term microstructural changes in solid oxide fuel cell anodes: 3D reconstruction

Journal of the American Ceramic Society (2017)

Harshil Parikh Naima Hilli Mark R. De Guire A. H. Heuer Zhien Liu

Abstract Microstructural changes in solid oxide fuel cell anodes after long‐term operation have been characterized by sequential sectioning with a focused ion beam, followed by scanning electron microscopy imaging and three‐dimensional reconstruction. The anodes were porous composites of Ni and Y 2 O 3 ‐stabilized ZrO 2 ( YSZ ). The cells were operated at 800°C for 2, 4, and 8 kh, and at 925°C for 2 and 4 kh. For each specimen, the volume fraction, surface area, particle diameter, and tortuosity have been calculated for each phase (Ni, YSZ , and pores). The dependence of these microstructural parameters on the volume of sample analyzed was monitored; sufficiently large volumes were analyzed so as to eliminate any effect of sample volume. Gradients in volume fraction of Ni and porosity developed during fuel cell operation, with Ni fraction increasing, and pore fraction decreasing, at the electrolyte/anode interface. The magnitudes of these gradients increased with time.

Volume fraction

Tortuosity

10.1111/jace.14659

Cite

Citations (9)

The Effects of Seeding on the Formation of High-T_c Bi-Pb-Sr-Ca-Cu-O Compounds

MRS Proceedings (1989)

Cheol J. Kim Mark R. De Guire Narottam P. Bansal

10.1557/proc-169-333

Cite

Citations (0)

Point defect analysis and microstructural effects in pure and donor-doped ceria

Solid State Ionics (1992)

Mark R. De Guire M.J. Shingler Esin Dincer

10.1016/0167-2738(92)90101-t

Cite

Citations (26)

Solid‐State Diffusive Amorphization in TiO₂/ZrO₂ Bilayers

Journal of the American Ceramic Society (1996)

Hyunjung Shin Monika Agarwal Mark R. De Guire A. H. Heuer

Thin films of crystalline TiO 2 were deposited on self‐assembled organic monolayers from aqueous TiCl 4 solutions at 80°C; partially crystalline ZrO 2 films were deposited on top of the TiO 2 layers from Zr(SO 4 ) 2 solutions at 70°C. In the absence of a ZrO 2 film, the TiO 2 films had the anatase structure and underwent grain coarsening on annealing at temperatures up to 800°C; in the absence of a TiO 2 film, the ZrO 2 films crystallized to the tetragonal polymorph at 500°C. However, the TiO 2 and ZrO 2 bilayers underwent solid‐state diffusive amorphization at 500°C, and ZrTiO 4 crystallization could be observed only at temperatures of 550°C or higher. This result implies that metastable amorphous ZrTiO 4 is energetically favorable compared to two‐phase mixtures of crystalline TiO 2 and ZrO 2 , but that crystallization of ZrTiO 4 involves a high activation barrier.

Tetragonal crystal system

Metastability

10.1111/j.1151-2916.1996.tb08023.x

Cite

Citations (23)

Synthesis of ZrO{sub 2} and Y{sub 2}O{sub 3}-doped ZrO{sub 2} thin films using self-assembled monolayers

Journal of the American Ceramic Society (1997)

Monika Agarwal Mark R. De Guire A. H. Heuer

Undoped or Y{sub 2}O{sub 3}-doped ZrO{sub 2} thin films were deposited on self-assembled monolayers (SAMs) with either sulfonate or methyl terminal functionalities on single-crystal silicon substrates. The undoped films were formed by enhanced hydrolysis of zirconium sulfate (Zr(SO{sub 4}) {center_dot} 4H{sub 4}O) solutions in the presence of HCl at 70 C. Typically, these films were a mixture of two phases: nanocrystalline tetragonal- (t-) ZrO{sub 2} and an amorphous basic zirconium sulfate. However, films with little or no amorphous material could be produced. The mechanism of film formation and the growth kinetics have been explained through a coagulation model involving homogeneous nucleation, particle adhesion, and aggregation onto the substrate. Annealing of these films at 500 C led to complete crystallization to t-ZrO{sub 2}. Amorphous Y{sub 2}O{sub 3}-containing ZrO{sub 2} films were prepared from a precursor solution containing zirconium sulfate, yttrium sulfate (Y{sub 2}(SO{sub 4}){sub 3} {center_dot} 8H{sub 2}O), and urea (NH{sub 2}CONH{sub 2}) at pH 2.2--3.0 at 80 C. These films also were fully crystalline after annealing at 500 C.

Nanocrystalline material

Tetragonal crystal system

Source

Cite

Citations (0)

Journal of Electroceramics (2001)

T. P. Niesen Mark R. De Guire

Deposition

Selenide

10.1023/a:1011496429540

Cite

Citations (317)

Ultrasonic Evaluation of Oxygen Content, Modulus, and Microstructure Changes in YBa₂Cu₃O_7–x Occuring During Oxidation and Reduction

Journal of the American Ceramic Society (1992)

Don J. Roth Mark R. De Guire Leonard E. Dolhert

Ultrasonic velocity measurements were used to evaluate the effects of oxidation and reduction on the oxygen content, elastic properties, and global microstructure of the YBa 2 Cu 3 O 7– x ceramic superconductor for samples ranging from 70% to 90% of theoretical density. Bulk density, velocity, and Young's modulus generally increased with increasing oxygen content upon oxidation, and this behavior was reversible. Velocity image patterns obtained from ultrasonic scans were similar after oxidation and reduction treatments for a 90% dense sample, although the velocity value at any given point on the sample was changed following the treatments. The unchanging pattern correlated with destructive measurements showing that the spatial pore distribution (fraction and size) was not measurably altered after the treatments. Changes in superconducting behavior, crystal structure, and grain structure were observed consistent with changes in oxygn content.

10.1111/j.1151-2916.1992.tb05557.x

Cite

Citations (1)