Self-cleaning mass calibration of a thermogravimetric device using a thin-film molybdenum

This paper presents a self-cleaning mass calibration procedure for a thermogravimetric (TC) device using molybdenum (Mo). A Mo thin-film is deposited by sputtering and patterned with known geometry on the device sample area using a standard lithography step thus giving accurate control of the mass of the sample under investigation. The device resonance frequency is measured while the temperature of the sample area is increased from room temperature to about 923 K using the integrated heater. First the Mo oxidizes. Then, at temperatures above 773 K the Mo trioxide (MoO₃) evaporates. This causes a shift in resonance frequency that can be linked to the known initial mass of the Mo. An advantage of this method is that, the Mo leaves the device clean and ready for TG analysis (TGA) of other samples.