Thesis

For graduate students, the doctoral thesis is the culmination of many years’ work.

Here is my Ph.D. thesis, published at the University of Illinois at Urbana-Champaign in 1998, entitled “Growth and magneto elastic behavior of b-axis dysprosium”:

Although this thesis is now over 15 years old, I stand behind most – but not all – of the work today. In particular, the “industry standard” analysis of the thermodynamics of the magnetic phase transition (around page 137) was flat out wrong.  Shortly after writing the thesis, I discovered a brilliant old publication by Landau and Devonshire, who address the correct way to treat the phase transition using the Gibbs free energy.  Their original work applied to clamped piezoelectric films – and in my case I had clamped magnetostrictive films – but the phase transition is in both cases a first order one, and the underlying mechanism does not change the validity of their result. I applied their calculations to my own data, and I found their results matched my data perfectly.  I have not yet published this new result.