Research Experiences for Undergraduates
Project Title: Hall Effect and ScN
Student Name: Andrew Moore
Studentís home institution: Hope College
Research Advisor(s): Dr. Mark E. Little
Source of Support: NSF-REU
At the beginning of the summer the goal of the research was to design and build an experiment that would create a hall effect in a sample, and take a number of measurements. This was achieved through the construction of an apparatus that would hold a sample inside a magnet, and the writing of a program that would run a given current across the sample, take voltage measurements, and calculate the hall constant, hall mobility, carrier density, and conductivity. Some problems were encountered while trying to make ohmic contact to the sample, which was finally remedied by way of gold pushpins. It was decided that scandium nitride would be tested for how different growth variables, growth time, wattage, temperature, and nitrogen/argon gas ratio, affect the final film. It was found that the hall mobility increased as the wattage increased, no other patterns were found. It was hypothesized that the conductivity of the film would increase as the growth temperature went up. The hypotheses held true for samples grown at 450 and 650 degrees Celsius, but sample grown around 850 degrees Celsius conducted well in the low voltage regime, but outside this region they acted like a capacitor. It is intended to look into this behavior more in the future along with further temperature dependant studies of scandium nitride.
Slide show of Andrew Moore's work (Requires Microsoft PowerPoint or a PowerPoint viewer.)