Ag-doped ZnO (ZnO:Ag) films are prepared on c-plane sapphire substrates by pulsed laser deposition at different substrate temperatures. The effect of substrate temperature on the ZnO:Ag film is studied in detail by EDX, XRD and Raman spectroscopy. The results reveal that raising the substrate temperature is beneficial for incorporating Ag into ZnO:Ag films in the range of our experimental temperatures and a number of Ag atoms incorporation into ZnO:Ag films may cause the (002) peak positions of the XRD spectra shift to a lower angle direction, but hardly affect the c-axis orientation of the films. The (002) peak shift ought to be due to the increase of lattice constant in the c-axis direction caused by the partial substitution of Zn2+ ions by Ag+ ions. In addition, a local vibrational mode (LVM) at 492 cm−1 induced by doping Ag occurred in the Raman spectra of all the ZnO:Ag films and its peak position hardly shifted with increasing substrate temperature. It means that the LVM can act as an indication of Ag incorporation into ZnO:Ag film.
The purpose of this paper is to show the investigation on a type of unitary piezoelectric four-component cutting dynamometer. Based on piezoelectric effect of quartz crystal, such as torsion effect, transverse effect, lengthways effect and shearing effect, horizontal moment and three-direction orthogonal forces carried on the dynamometer during cutting process can be measured simultaneously. The dynamometer can be used to measure forces and horizontal moments in drilling, grinding, milling, turning. A secondary purpose is to optimize structure parameters of the dynamometer by ANSYS. The dynamometer has good performance with high sensitivity, good linearity and repeatability and low crosstalk after optimizing.
We present a simple one-step selective liquid-phase epitaxy (LPE) method to prepare peelable GaAs pyramidal microtips for compact scanning near-field optical microscopy (SNOM). A high Al content AlGaAs thin layer, as an etching sacrificial layer, is firstly selectively grown in periodic square windows of SiO 2 mask deposited on GaAs substrate, and then GaAs is grown on the AlGaAs layer to automatically form peelable pyramidal microtip array. After the growth of the microtip array, the wafer is immersed into concentrated HCl solution at ice-point temperature to selectively etch off the AlGaAs layer and separate the microtips from the substrate. Scanning electron microscopy (SEM) images show that the microtips grown and peeled by this method are similarly high in quality with the peelable microtips prepared by two-step growth process we have reported before, but the one-step growth process is simpler and cheaper.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.