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Full-Text Articles in Mechanical Engineering

Nanoindentation Of The A And C Domains In A Tetragonal Batio3 Single Crystal, Young-Bae Park, Matthew J. Dicken, Zhi-Hui Xu, Xiaodong Li Oct 2007

Nanoindentation Of The A And C Domains In A Tetragonal Batio3 Single Crystal, Young-Bae Park, Matthew J. Dicken, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

Nanoindentation in conjunction with piezoresponse force microscopy was used to study domain switching and to measure the mechanical properties of individual ferroelectric domains in a tetragonal BaTiO3 single crystal. It was found that nanoindentation has induced local domain switching; the a and c domains of BaTiO3 have different elastic moduli but similar hardness.Nanoindentationmodulus mapping on the a and c domains further confirmed such difference in elasticity. Finite element modeling was used to simulate the von Mises stress and plastic strain profiles of the indentations on both a and c domains, which introduces a much higher stress level ...


Elastic Modulus Of Amorphous Sio2 Nanowires, Hai Ni, Xiaodong Li, Hongsheng Gao Jan 2006

Elastic Modulus Of Amorphous Sio2 Nanowires, Hai Ni, Xiaodong Li, Hongsheng Gao

Faculty Publications

Amorphous SiO2 nanowires with diameter ranging from 50 to 100 nm were synthesized using chemical vapor deposition(CVD) under an argon atmosphere at atmospheric pressure. Nanoscale three-point bending tests were performed directly on individual amorphous SiO2 nanowires using an atomic force microscope (AFM).Elastic modulus of the amorphous SiO2 nanowires was measured to be 76.6±7.2GPa, which is close to the reported value of the bulk SiO2 and thermally grown SiO2 thin films, but lower than that of plasma-enhanced CVD SiO2 thin films. The amorphous SiO2 nanowires exhibit brittle fracture failure ...


Top-Down Structure And Device Fabrication Using In Situ Nanomachining, Xiaodong Li, Xinnan Wang, Qihua Xiong, Peter C. Eklund Dec 2005

Top-Down Structure And Device Fabrication Using In Situ Nanomachining, Xiaodong Li, Xinnan Wang, Qihua Xiong, Peter C. Eklund

Faculty Publications

We demonstrate the potential of an alternative tool for the fabrication of nanoscale structures and devices. A nanoindenter integrated with an atomic force microscope is shown to be a powerful machine tool for cutting precise length nanowires or nanobelts and for manipulating the shortened wires. We also demonstrate its utility in cutting grooves and fabricating dents (or periodic arrays of dents) in ZnSnanobelts. This approach permits the direct mechanical machining of nanodevices that are supported on a substrate without the inherent complications of e beam or photolithography.


Structural Characterization Of Aluminum Films Deposited On Sputtered-Titanium Nitride/ Silicon Substrate By Metalorganic Chemical Vapor Deposition From Dimethylethylamine Alane, Xiaodong Li, Byoung-Youp Kim, Shi-Woo Rhee Dec 1995

Structural Characterization Of Aluminum Films Deposited On Sputtered-Titanium Nitride/ Silicon Substrate By Metalorganic Chemical Vapor Deposition From Dimethylethylamine Alane, Xiaodong Li, Byoung-Youp Kim, Shi-Woo Rhee

Faculty Publications

Alfilmsdeposited on sputtered‐TiN/Si substrate by metalorganic chemical vapor deposition(MOCVD) from dimethylethylamine alane (DMEAA) were characterized using x‐ray diffraction(XRD),Auger electron spectroscopy(AES),atomic force microscopy(AFM), and transmission electron microscopy (TEM). The TiN filmsputtered on the Si has a preferred orientation along the growth direction with the 〈111〉 of the film parallel to the Si〈111〉. Sputtering of the TiN film on the Si induced strains at the interface. The TiN/Si interface is flat while the Al/TiN interface is rough. There exist many dislocations at the Al/TiN interface. The Al2O ...