Xinyi Zhang

Synthesis and piezoresponse of highly ordered Pb(Zr0.53Ti0.47)O3 nanowire arrays

We report the synthesis and characterization of ferroelectric lead zirconate titanate PbsZr0.53Ti0.47dO3 (PZT) nanowires. The PZT nanowires, with diameters of about 45 nm and lengths of about 6 mm, were fabricated by means of a sol-gel method utilizing nanochannel alumina templates. After postannealing at 700 ° C, the PZT nanowires exhibit a polycrystalline microstructure, and x-ray diffraction and transmission electron microscopy study revealed their perovskite crystal structure. The piezoelectric characteristics of individual PZT nanowires were demonstrated by piezoresponse force microscopy.

Synthesis and ferroelectric properties of multiferroic BiFeO3 nanotube arrays

We report the synthesis and characterization of ordered multiferroic BiFeO3 (BFO) nanotube arrays. BFO nanotubes with diameters of about 250nm and lengths of about 6μm were fabricated by means of a sol-gel method utilizing nanochannel alumina templates. After postannealing at 700°C, the BFO nanotubes exhibited a polycrystalline microstructure, and x-ray diffraction and transmission electron microscopy study revealed that they are of a perovskite crystal structure. Significant ferroelectric and piezoelectric characteristics of BFO nanotubes have been demonstrated by means of piezoresponse force microscopy measurement.

Hierarchical Porous Plasmonic Metamaterials for Reproducible Ultrasensitive Surface‐Enhanced Raman Spectroscopy

Hierarchical porous plasmonic metamaterials consisting of periodic nanoholes with tunable diameter and uniformly distributed mesopores over the bulk are developed as a new class of 3D surface-enhanced Raman spectroscopy (SERS) substrates. This multiscale architecture not only facilitates efficient cascaded electromagnetic enhancement but also provides an enormous number of Raman-active binding sites, exhibiting excellent reproducibility and ultrasensitive detection of aromatic molecules down to 10(-13) M.