In situ probing of electromechanical properties of an individual ZnO nanobelt

We report here, an investigation on electrical and structural-microstructural properties of an individual ZnO nanobelt via in situ transmission electron microscopy using an atomic force microscopy (AFM) system. The I-V characteristics of the ZnO nanobelt, just in contact with the AFM tip indicates the insulating behavior, however, it behaves like a semiconductor under applied stress. Analysis of the high resolution lattice images and the corresponding electron diffraction patterns shows that each ZnO nanobelt is a single crystalline, having wurtzite hexagonal structure (a=0.324 nm, c=0.520 66 nm) with a general growth direction of (1010)

COMPARE THE BEHAVIOR FACTOR OF THE ULTIMATE RESISTANCE OF MOMENT FRAME, PLAIN AND PERFORATED STEEL PLATE SHEAR WALLS AND BUCKLING RESTRAINED BRACE AS YIELDING METAL DAMPER

Steel moment frame systems, steel plate shear walls and also buckling restrained brace (BRB) are considered as the most widely used seismic resistant systems of the world. Firstly, in this research, in order to validate the finite element models, the tested sample of steel plate shear walls of 4 floors at the University of Alberta, Canada, and the tested sample of buckling restrained brace at the University of Berkeley California, with the software ABAQUS 6.10-1 were used. Then, the obtained results of the test and analysis have been compared. The confirmed models have been used for the analysis of two-dimensional frame of plain and perforated steel plate shear walls with a regular pattern of positing holes in the screen, buckling restrained brace and moment frame of 4 floors

In situ probing of electromechanical properties of an individual ZnO nanobelt

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010

A study on the structure-piezoresponse property of a ZnO nanobelt by in situ transmission rlectron microscopy

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011

In situ probing of structural and electromechanical properties of an individual ZnO nanobelt

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011

On the correlation of crystal defects and band gap properties of ZnO nanobelts

We report here investigations of crystal and electronic structure of as-synthesized and annealed ZnO nanobelts by an in-situ high-resolution transmission electron microscope equipped with a scanning tunneling microscopy probe. The in-situ band gap measurements of individual ZnO nanobelts were carried out in scanning tunneling spectroscopy mode using the differential conductance dI/dV–V data. The band gap value of the as-synthesized ZnO nanobelts was calculated to be ∼2.98 eV, while this property for the annealed nanobelts (∼3.21 eV) was close to the band gap value for bulk ZnO materials (∼3.37 eV). The difference in the band gap value of the as-synthesized ZnO nanobelts and annealed ones was attributed to the planar defects (e.g. stacking faults and twins). These defects can alter the electronic structure by producing localized resonant states that result in band gap reduction

Structural inhomogeneity and piezoelectric enhancement in ZnO nanobelts

In this work, piezoelectricity of individual ZnO nanobelts grown along the [0 1 ī 0] direction is studied using piezoresponse force microscopy (PFM). It is found that the effective piezoelectric coefficient of these NBs, d_33^eff, is increasing from 2.7 pm/V at 30 kHz to 44 pm/V at 150 kHz. The results were explained by the Debye model, where structural inhomogeneity in our NBs was shown to be responsible for piezoelectric enhancement