Naveen Palapati, Ph.D. profile photo

Naveen Palapati, Ph.D.

Assistant Professor, Department of Mechanical and Nuclear Engineering

Engineering East Hall, Room E3236, Richmond, VA, US

(804) 827-5276 palapatinkr@vcu.edu

Material engineering expert with specializing in nanotechnology

Publications

Documents

Photos

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Audio

Video

Social

Industry Expertise

  • Research
  • Nanotechnology
  • Education/Learning

Areas of Expertise

NanotechnologyNanoscale lithium-ion batteriesNanomanipulationMaterial CharacterizationFabrication of nanoscale devicesMaterial Engineering

Accomplishments

Alpha Epsilon Lambda | professional

Inducted 04/29/16 (Top 1% in VCU)

Education

Victoria Commonwealth University

Ph.D., Mechanical and Nuclear Engineering

2011

GRIET/JNTU, Hyderabad, India

B.S., Mechanical Engineering

2008

Affiliations

  • Grad Mechanical and Nuclear Engineering Association (GradMNEA) VCU: President
  • Engineering Graduate Student Association (EGSA) VCU: Vice President and Secretary
  • Tiranga-Indian Nationals at VCU: Advisor General Secretary Webmaster

Selected Articles

Super-giant magnetoresistance at room-temperature in copper nanowires due to magnetic field modulation of potential barrier heights at nanowire-contact interfaces | Nanotechnology

2016

We have observed a super-giant (~10 000 000%) negative magnetoresistance at 39 mT field in Cu nanowires contacted with Au contact pads. In these nanowires, potential barriers form at the two Cu/Au interfaces because of Cu oxidation that results in an ultrathin copper oxide layer forming between Cu and Au. Current flows when electrons tunnel through, and/or thermionically emit over, these barriers. A magnetic field applied transverse to the direction of current flow along the wire deflects electrons toward one edge of the wire because of the Lorentz force, causing electron accumulation at that edge and depletion at the other. This lowers the potential barrier at the accumulated edge and raises it at the depleted edge, causing a super-giant magnetoresistance at room temperature.

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The role of electronic and ionic conductivities in the rate performance of tunnel structured manganese oxides in Li-ion batteries | APL Materials

2016

Single nanowires of two manganese oxide polymorphs (α-MnO2 and todorokite manganese oxide), which display a controlled size variation in terms of their square structural tunnels, were isolated onto nanofabricated platforms using dielectrophoresis. This platform allowed for the measurement of the electronic conductivity of these manganese oxides, which was found to be higher in α-MnO2 as compared to that of the todorokite phase by a factor of ∼46. Despite this observation of substantially higher electronic conductivity in α-MnO2, the todorokite manganese oxide exhibited better electrochemical rate performance as a Li-ion battery cathode. The relationship between this electrochemical performance, the electronic conductivities of the manganese oxides, and their reported ionic conductivities is discussed for the first time, clearly revealing that the rate performance of these materials is limited by their Li+ diffusivity, and not by their electronic conductivity. This result reveals important new insights relevant for improving the power density of manganese oxides, which have shown promise as a low-cost, abundant, and safe alternative for next-generation cathode materials. Furthermore, the presented experimental approach is suitable for assessing a broader family of one-dimensional electrode active materials (in terms of their electronic and ionic conductivities) for both Li-ion batteries and for electrochemical systems utilizing charge-carrying ions beyond Li+.

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Young’s modulus of [111] germanium nanowires | ALP Materials

2015

This paper reports a diameter-independent Young’s modulus of 91.9 ± 8.2 GPa for [111] Germanium nanowires (Ge NWs). When the surface oxide layer is accounted for using a core-shell NW approximation, the YM of the Ge core approaches a near theoretical value of 147.6 ± 23.4 GPa. The ultimate strength of a NW device was measured at 10.9 GPa, which represents a very high experimental-to-theoretical strength ratio of ∼75%. With increasing interest in this material system as a high-capacity lithium-ion battery anode, the presented data provide inputs that are essential in predicting its lithiation-induced stress fields and fracture behavior.

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