| Author(s): |
Takeshi Nishimatsu; U Waghmare; Yoshiyuki Kawazoe; Benjamin P. Burton; Kazutaka Nagao; N. Saito; |
| Title: |
Ferroics: Magnetic-Compass Lattice and Optical Phonon Dispersions of Dipolar Crystals |
| Published: |
Date Unknown |
| Abstract: |
We report a simple safe and attractive pedagogic demonstration with magnetic compasses that facilitates an intuitive understanding of the concept that ferromagnetism and ferroelectricity do not result from dipole-dipole interactions alone. Phonon dispersion relations were calculated for a 3-dimensional simple-cubic dipole crystal and a 2-dimensional square-lattice dipole crystal. The latter calculation corresponds to the compass demonstration that confirm the antiferro ground state structure. A sum rule for the three optical phonon frequencies is discussed. A mathematical non-analyticity in the longitudinal optical phonon are also illustrated. |
| Citation: |
American Journal of Physics |
| Volume: |
66 |
| Keywords: |
dipole-dipole interactions;ferroelectricity;ferromagnetism;phonons |
| Research Areas: |
Characterization, Ceramics |
