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