Temperature-Controlled Scanning Electrochemical Microscope
For studying the temperature dependences of interfacial processes a home-built SECM set-up has been modified to facilitate an accurate control of the temperature of the examined sample. The developed instrument takes advantage of a peltier element, which is situated below the measuring cell and used to increase or decrease the temperature of the attached sample in the measuring cell. A peltier element was chosen because it allows establishing fast temperatures changes. The combination with a computer-controlled temperature controller enables the set-up to approach and maintain the desired setpoint with a high-precision. The system is based on a conventional SECM set-up equipped with 3 stepper motors (nominal resolution 0.625µm) and an additional piezo stack for the fine-positioning in z-direction. Utilizing a function generator, a lock-in amplifier and a pair of piezos enables a shearforce based distance control. The main components used for the temperature control are the temperature controller (A), an aluminium cube serving as heat reservoir (B) containing the peltier element and a thin metal plate (D) which embeds the temperature sensor and is used for the heat transfer to the measuring cell. The sample is pressed upon the metal plate (D) by the acrylic glass block (C). The measuring cell holding the electrolyte is therefore formed by the sample itself and the walls of a bore drilled into the plexiglass.