Picture about frustrated magnetism

Frustrated magnetic materials are an excellent playground for putting theoretical models through rigorous tests, and for searching for new and unexpected properties and phenomena. Magnetic frustration occurs when all of the simple pairwise magnetic interactions cannot be satisfied simultaneously and so the eventual magnetic ground-state ends up being a compromise. Often several degenerate or close-in-energy states compete, resulting in unexpected properties. The first step though is finding and preparing materials and systems that embody the idealised theoretical models of a specific lattice of magnetic ions, with specific interaction type and strength. Lattices built from triangles are often frustrated, such as the 2D triangular and Kagome lattices, or the 3D pyrochlore lattice. Example publications include:

The A3C60 fullerides, where A is an alkali metal such as Na, K, Rb or Cs, show superconductivity with a maximum temperature of 38 K (in A15-structure Cs3C60, under ~1 kBar pressure).

The superconductivity is thought to be conventional BCS type, mediated by electron-phonon coupling, but surprisingly, the superconducting dome emerges from a Mott-insulating state in the most expanded members, much like the cuprates and other unconventional superconductors. Electron-electron correlations certainly play an important role in the highly expanded fullerides. They continue to be important materials to study in the search for understanding electron-electron mediated unconventional superconductivity. Example publications include:

Something about shape memory alloys.
Example publications include: