It has been reported that only nano tungsten needle having sharp tip and single atom at the apex can provide stable and reliable atomically resolved imaging for applications of scanning tunneling microscopy (STM). Well, do you know how to prepare such a nano tungsten needle? Differing from the traditional methods, the experts have proposed a new method for preparing nano tungsten needles:
More details, please visit:
http://tungsten.com.cn/tungsten-needles.html
The principle of the new preparation method is: On the basis of electrochemical etching, the field etching technology is further adopted to sharpen the needle tip. A high-purity tungsten wire with diameter of 0.2mm was selected as the raw material, and then a needle tip with a radius of curvature better than 50nm was obtained using an electrochemical etching method. Then, a field ion microscope is used to perform field etching. According to the imaging during the etching process, the size of the needle tip can be judged in real time to obtain a nano tungsten tip with a specific nanometer size. In this way, atomic resolution imaging can be performed on a field ion microscope.
