A reverse electrochemical floating-layer technique of SPM tip preparation

An experimental set-up involving a combination of reverse electrochemical e tching and the floating-layer technique of tip preparation is presented. In the model only de bias is used, avoiding the shortcomings of ac bias. The collection of two tips in a single etching process and mechanical auto-brea king of the circuit are emphasized. This cost and time effective, easy in-l aboratory approach yields two sharp tips without paying attention to switch ing off the circuit. The nature of the tip shape arising from the floating- layer technique has been explained in terms of the electrical field distrib ution between the electrodes. The addition of some new information together with a few established facts will enrich and enlighten the art of tip prep aration.