PID Algorithmic Control of Temperature to Examine the Phase-Changing Properties of Vanadium Dioxide
presented by Tristan Carlson C'20
Wednesday, April 3, 7:30 - 8:30pm, Woods Labs 216
Vanadium dioxide (VO2) is a widely studied phase-changing material that transitions from an insulator to a metal at a nominal critical temperature (Tc) of 67 °C. Starting in a monoclinic crystal structure, VO2 changes into a tetragonal crystal structure as its temperature increases beyond Tc. The transition into the metallic phase also results in increased electrical conductivity and magnetic susceptibility but decreased infrared transmission. The phase change can take place on an ultrafast timescale (< 10-13 s), which holds promise for applications in optical switching and information storage.
In this talk, I will discuss how I created a Proportional-Integral-Derivative (PID) temperature controller using the LabVIEW graphical programming environment to maintain a constant temperature within a hundredth of a degree. The precision of the temperature control allowed for a close examination of the phase-transition hysteresis of infrared light transmitted through a 40-nm-thin VO2 film.
Jarrod Irwin, C’20, is a junior physics major at the University of the South from Short Hills, New Jersey. He is a member of the Sigma Nu fraternity and has previously served on its executive board. He is the current president of the Sewanee chapter of the Society of Physics Students.