Micropulsed system for studying thermal properties of metallic nano-films at room conditions

An electronic system for applying electrical current pulses with fixed time between 10 and 500 μs on metallic films is described. The system is capable to measure changes on the electrical resistance (i.e, temperature) at room temperature and atmospheric pressure, when micropulses are applied on the nano-thickness metallic films deposited on thick substrates. The proposed electronic system is mainly formed by three sections: the micropulses generator section which works with a PIC 16F84A device, the signals processor section (AD712 and LT1210 amplifiers, and an AD734 multiplier/divider), and the data acquisition section integrated by a digital oscilloscope Tektronix model DPO 4050. By applying controlled micropulses on the metallic films and measuring the corresponding changes of the electrical resistance, which are converted at temperature, it is possible to determine the heat capacity of the metallic films at nano-dimensional scale. The proposed electronic system is used to characterize gold thin films deposited on polymeric substrates. Preliminary results determine a heat capacity value of 118 ± 7 nJ/°C for a 100 nm-gold film.