This essay discusses recent work on bismuth ferrite, which reveals theoretically and experimentally a phase transition under stress that does not change symmetry but changes the c/a lattice constant ratio. As shown by Ishibashi, such transitions must be discontinuous and are described by free energies eighth-order in polarization P. Such a predicted two-step change in P is also known in potassium nitrate films.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.