Joshua L Cohn

Professor
Chairman of Department of Physics

Phone:
(305) 284-7123
Locator Code:
0530

 
About
My research involves measuring low-temperature electronic, magnetic, and thermal properties of novel materials that manifest interesting physics and show some potential to be useful in future electronic devices. These physical properties measurements, like electrical conductivity, thermal conductivity, and thermoelectricity, involve attaching very small wires to small crystalline specimens (mm sized), cooling them in liquid cryogens (liquid nitrogen and liquid helium), and using specialized voltmeters, current sources, and occasionally high-field magnets to study their properties. A separate research effort involves making "thin films" of some of these same materials -- thin coatings of 100 or so atomic layers of a material of interest deposited on a crystalline insulating surface. The method of deposition involves a high-powered laser that vaporizes a "target" of the material of interest inside a high-vacuum chamber (pulsed-laser deposition). We study these films using x-ray crystallography (to determine their structural properties) and measure their low-temperature properties with the techniques mentioned above. Thin films are a first step toward making useful devices.
Career

Education

1989Ph.D. Physics, with distinction University of Michigan
B.A. Physics, with honors Wesleyan University, Middletown, CT

Professional Experience

- Co-Founder, University of Miami Center for Advanced Microscopy
2010 - 2013Professor and Associate Chair, University of Miami, Department of Physics
2004 - 2010Professor, University of Miami, Department of Physics
1998 - 2004Associate Professor, University of Miami, Department of Physics
1992 - 1998Assitant Professor, University of Miami, Department of Physics
1985 - 1989Research Assistant, University of Michigan, Department of Physics
1983 - 1986Teaching Assistant, University of Michigan, Department of Physics
1981 - 1983Research Assistant, Wesleyan University, Department of Physics
1981 - 1983Teaching Assistant, Wesleyan University, Department of Physics
1989 - 1992Postdoctoral Fellow, Naval Research Laboratory

Honors & Acknowledgements

University of Miami 2011 Provost Research Award (2010)
Outstanding Referee, American Physical Society (240 selected out of 40,000) (2009)
University of Miami Research Council Summer Research Award (2005)
University of Miami Research Council General Research Award (1994)
University of Miami Research Council Summer Research Award in Natural Sciences and Engineering (1994)
University of Miami Research Council Summer Research Award in Natural Sciences and Engineering (1993)
Knight Faculty Fellow, University of Miami (1992)
Co-author of “Understanding Superconductivity in the Cuprates: Theory and Experiment,” selected as most outstanding article in the annual Naval Research Laboratory Review (1992)
Nominee for outstanding Ph.D thesis in Physics, University of Michigan (1989)
Bertman Prize in Physics, Wesleyan University (1983)
Inducted Member, Sigma Xi, Wesleyan University (1983)

Conferences & Events

Jan. 7-13, 1999
University of Miami HTS99, Conference on High-Temperature Superconductivity and, other Oxides | Coral Gables, FL.
Co-organizer
Jan. 5-11, 1995
University of Miami Workshop on High-Temperature Superconductivity: Physical Properties and Mechanisms | Coral Gables, FL
Co-organizer

Memberships

Member, American Physical Society
Member, Materials Research Society
Member, American Association of Physics Teachers
Research

LIST OF SPECIALTIES: Transport, magnetic, and dielectric studies of correlated and low-dimensional systems, Superconducting and mangetic oxides, Thermoelectrics, Disorder, weak localization, electron-electron interaction effects, percolation in granular metal films; intergrain tunnel resistance and charging energy (Coulomb blockade)

Research Projects

Funded Research

Department of Energy, Basic Energy Sciences, 9/15/15-9/14/18, $455,823
“Thermoelectric Effects and Spin-mediated Transport in Oxide
Conductors and Insulators”
Principal Investigator: J. L. Cohn


Department of Energy, Basic Energy Sciences, 9/15/12-9/14/15, $395,000
“Extreme Thermoelectric Behavior in Low-Dimensional Oxide Conductors”
Principal Investigator: J. L. Cohn


Research Corporation Opportunity Award, 11/6/05-12/31/09, $75,000
“Dielectric Studies of Low-Dimensional and Competing-Order
Ground States in Transition-Metal Oxides
Principal Investigator: J. L. Cohn


National Science Foundation, 9/1/00-8/31/04, $297,000
“Transport and Magnetic Studies of Phase Separation
and Electron Correlations in Magnetic and
Superconducting Oxides,”
Principal Investigator: J. L. Cohn


National Science Foundation, 9/1/98-12/31/02, $360,000
“Molecular Materials from Complexes with Bipyridine-like
Ligands: Novel Electrides,”
Principal Investigator: L. Echegoyen (Chemistry Department)
Co-Principal Investigator: J. L. Cohn


National Science Foundation, 9/1/96-8/31/00, $235,000,
“Thermal Transport in Copper and Manganese Oxides:
Lattice Interactions and the Superconducting and
Magnetic Phase Behavior,”
Principal Investigator: J. L. Cohn


Defense Advanced Research Projects Admin. through the Office
of Naval Research, 12/20/98-12/19/99, $5,000
“University of Miami Conference on High-Temperature
Superconductivity and Related Topics, 7-13 January, 1999,”
Principal Investigator: J. L. Cohn
Co-PI’s: J. Ashkenazi, S. Barnes, F. Zuo


Marlow Industries, Inc., 8/1/98-7/31/99, $9,000
Financial Agreement between UM and Marlow for
measurements of transport properties of thermoelectrics,
Project Coordinator for UM: J. L. Cohn


Naval Research Laboratory, 9/1/95-10/31/97, $20,000,
“Development and Application of an AC-Technique for
Measuring Thermal Conductivity of Superconducting and
Cryocooling Materials,”
Principal Investigator: J. L. Cohn


National Science Foundation, 6/1/95-5/31/96, $130,000,
“Acquisition of a Pulsed Laser Deposition System
and an X-ray Diffractometer,”
Principal Investigator: J. L. Cohn


Office of Naval Research, 12/15/94-12/14/95, $7,673
“University of Miami Workshop on High-Temperature
Superconductivity:Physical Properties and Mechanisms,”
Jan. 5-11, 1995 Coral Gables, FL,
Principal Investigator: J. L. Cohn
Co-PI’s: J. Ashkenazi, S. Barnes, F. Zuo

Editorial Responsibilities
Co-editor, Proceedings of the University of Miami Conference on High-Temperature Superconductivity and Related Topics 7-13 January, 1999, (American Institute of Physics, Woodbury,
NY), Vol. 483.

Co-editor, Proceedings of the University of Miami Workshop on High-Temperature Superconductivity: Physical Properties and Mechanisms, Journal of Superconductivity, Vol. 8, No.’s 4 and 5 (1995).

Publications

S. Moshfeghyeganeh, A. N. Cote, J. J. Neumeier and J. L. Cohn "Anisotropic transport in the quasi-one-dimensional semiconductor Li0.33MoO3" 095105119 (Journal of Applied Physics. 2016). [Link]


S. H. Masunaga, A.Rebello, A.T.Schye, N.Prasai, J.J.Neumeier, and J.L.Cohn "“Heat capacity, thermal expansion and heat transport in the Han Blue (BaCuSi4O10): Observation of structural phase transitions" Journal of Physics and Chemistry of Solids 6985 (2015).


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