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Search Publications by: Gheorghe Stan (Fed)

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Displaying 1 - 25 of 43

Multi-scale alignment to buried atom-scale devices using Kelvin probe force microscopy

February 24, 2024
Author(s)
Pradeep Namboodiri, Jonathan Wyrick, Gheorghe Stan, Xiqiao Wang, Fan Fei, Ranjit Kashid, Scott Schmucker, Richard Kasica, Bryan Barnes, Michael Stewart, Richard M. Silver
Fabrication of quantum devices by atomic scale patterning with a Scanning Tunneling Microscope (STM) has led to the development of single/few atom transistors, few-donor/quantum dot devices for spin manipulation and arrayed few-donor devices for analog

Atomic force microscopy for nanoscale mechanical property characterization

November 10, 2020
Author(s)
Gheorghe Stan, Sean King
Over the past several decades, atomic force microscopy (AFM) has advanced from a technique used primarily for surface topography imaging to one capable of characterizing a range of chemical, mechanical, electrical, and magnetic material properties with sub

Doping of MoTe2 via surface charge-transfer in ambient air

March 19, 2020
Author(s)
Gheorghe Stan, Cristian Ciobanu, Sri Ranga Jai Likith, Asha Rani, Sergiy Krylyuk, Albert Davydov
Doping is a key process that facilitates the use of semiconductors for electronic and optoelectronic devices, by which the concentration and type of majority carriers (electrons or holes) can be modified controllably to achieve desired conduction

Thermal conductivity of entropy stabilized oxides: approaching the minimum limit in single crystal solid solutions through charge induced atomic-scale disorder

September 17, 2018
Author(s)
Gheorghe Stan, Jeffrey Braun, Christina Rost, Mina Lim, Ashutosh Giri, David Olson, George Kotsonis, Donald Brenner, Jon-Paul Maria, Patrick Hopkins
Manipulating a crystalline material’s configurational entropy though the introduction of unique atomic species can produce novel materials with desirable mechanical and electrical properties. From a thermal transport perspective, large differences between

PEGylation of zinc nanoparticles amplifies their ability to enhance olfactory responses to odorant

December 20, 2017
Author(s)
Melissa Singletary, Samantha Hagerty, Shinichiro Muramoto, Yasmine Daniels, William A. MacCrehan, Gheorghe Stan, June W. Lau, Oleg Pustovyy, Ludmila Globa, Edward E. Morrison, Iryna Sorokulova, Vitaly Vodyanoy
Responses of olfactory sensory neurons to odorants are intensely enhanced with the addition of small endogenous and engineered zinc nanoparticles, as shown by physiological experiments. The highest enhancement was recorded with 1.2 nm non-oxidized zinc

Nanoscale Structure-Property Characterization of a Nanopatterned Hybrid Organic-Inorganic Nanoporous Material

April 13, 2017
Author(s)
Gheorghe Stan, Richard S. Gates, Qichi Hu, Kevin Kjoller, Craig Prater, Alan Myers, Kanwal Singh, Ebony Mays, Sean W. King
The continued advancement of nanostructured materials and exploitation of nanoscale size effects will ultimately require understanding material structure-property relationships at the nanoscale. Despite a plethora of metrologies capable of characterizing

After oxidation, zinc nanoparticles lose their ability to enhance responses to odorants

September 20, 2016
Author(s)
Samantha Hagerty, Yasmine C. Daniels, Melissa Singletary, Oleg Pustovyy, Ludmila Globa, William A. MacCrehan, Shinichiro Muramoto, June W. Lau, Edward Morrison, Iryna Sorokulova, Vitaly Vodyanoy, Gheorghe Stan
Electrical responses of olfactory sensory neurons to odorants were examined in the presence of zinc nanoparticles of various sizes and degrees of oxidation. The zinc nanoparticles were prepared by the underwater electrical discharge method and analyzed by

Engineered metal nanoparticles in the sub-nanomolar levels kill cancer cells

April 18, 2016
Author(s)
Yasmine C. Daniels, William A. MacCrehan, Shinichiro Muramoto, Gheorghe NMN Stan, Vitaly Vodyanoy, Oleg Pustovyy
Zinc and copper metal nanoparticles were produced from bulk metal rods by an underwater high-voltage discharge method. The metal nanoparticles, with estimated diameters of 1 nm to 2 nm, were determined to be more than 85 % non-oxidized. Exposure of rat RG2

Silicon epitaxy on H-terminated Si (100) surfaces at 250deg C

March 31, 2016
Author(s)
Xiao Deng, Pradeep N. Namboodiri, Kai Li, Xiqiao Wang, Gheorghe Stan, Alline F. Myers, Xinbin Cheng, Tongbao Li, Richard M. Silver
Silicon on silicon growth at low temperatures has become increasing important due to its use to encapsulate buried nanoscale dopant devices. The performance of atomic scale devices is fundamentally affected by the quality of the silicon matrix in which the

Vertical 2D/3D Semiconductor Heterostructures based on Epitaxial Molybdenum Disulfide and Gallium Nitride

February 19, 2016
Author(s)
Dmitry A. Ruzmetov, Kehao Zhang, Gheorghe Stan, Berc Kalanyan, Ganesh R. Bhimanapati, Sarah M. Eichfeld, R A. Burke, Pankaj B. Shah, Terrance P. O'Regan, Frank J. Crowne, A. Glen Birdwell, Joshua A. Robinson, Albert Davydov, Tony G. Ivanov
When designing semiconductor heterostructures, it is expected that epitaxial alignment will facilitate low-defect interfaces and efficient vertical transport. Here, we report lattice-matched epitaxial growth of molybdenum disulfide (MoSub2) directly on

Assessing Electron Backscattered Diffraction and Confocal Raman Microscopy Strain Mapping Using Wedge-indented Si

February 17, 2016
Author(s)
Lawrence Henry Friedman, Mark D. Vaudin, Stephan J. Stranick, Gheorghe Stan, Yvonne B. Gerbig, William Alexander Osborn, Robert F. Cook
The accuracy of electron backscattered diffraction (EBSD) and confocal Raman microscopy (CRM) for small-scale strain mapping are assessed using the multi-axial strain field surrounding a wedge indentation in Si as a test vehicle. The strain field is

Nanoscale buckling of ultrathin low-k dielectric lines during hard-mask patterning

May 7, 2015
Author(s)
Gheorghe Stan, Cristian V. Ciobanu, Igor Levin, Mark van Veenhuizen, Alan Myers, Kanwal Singh, Christopher Jezewski, Barbara Miner, Sean King
Commonly known in macroscale mechanics, buckling phenomena are now frequently also encountered in the nanoscale world as reveled in today's cutting-edge fabrication of microelectronics. The description of nanoscale buckling requires precise dimensional and

Preparation of silver nanoparticle loaded cotton threads to facilitate measurement development for textile applications

January 26, 2015
Author(s)
Justin M. Gorham, Karen E. Murphy, Jingyu Liu, Dimitri Tselenchuk, Gheorghe NMN Stan, Thao M. Nguyen, Richard D. Holbrook, Michael R. Winchester, Robert F. Cook, Robert MacCuspie, Vincent A. Hackley
FOREWORD This NIST special publication (SP) is one in a series of NIST SPs that address research needs articulated in the National Nanotechnology Initiative (NNI) Environmental, Health, and Safety Research Strategy published in 2011 [1]. This Strategy

Mechanical property changes in porous low-k dielectric thin films during processing

October 15, 2014
Author(s)
Gheorghe Stan, Richard S. Gates, Premsagar P. Kavuri, Jessica Torres, David Michalak, Canay Ege, Jeff Bielefeld, Sean W. King
The design of future generations of Cu-low-k dielectric interconnects with reduced electronic crosstalk often requires engineering materials with an optimal trade off between their dielectric constant and elastic modulus. This is because the benefits

Intermittent contact resonance atomic force microscopy

May 23, 2014
Author(s)
Gheorghe Stan, Richard S. Gates
The intermittent contact resonance atomic force microscopy (ICR-AFM) mode proposed here is a new frequency modulation technique performed in scanning force controlled AFM modes like force volume or peak force tapping. It consists of tracking the change in

Nanoscale mechanics by tomographic contact resonance atomic force microscopy

January 23, 2014
Author(s)
Gheorghe NMN Stan, Santiago Solares, Bede Pittenger, Natalia Erina, Chanmin Su
We report on a quantifiable depth-dependent contact resonance AFM (CR-AFM) measurements over polystyrene-polypropylene (PS-PP) polymer blends to detail surface and sub-surface features in terms of elastic modulus and mechanical dissipation. The depth