Magnetic neutron diffraction under high pressure

Applying high pressure in neutron diffraction provides a microscopic understanding of the magnetic order and magnetic interactions in materials under extreme conditions. By checking the dependence of interactions over a wide range of interatomic distances, this technique also allows testing microscopic models at ambient pressure. Recent instrumental progress in high pressure neutron diffraction now allows magnetic materials to be measured in an unprecedented range of pressures, possibly combined with very low temperatures and high magnetic fields. A few examples chosen in model ferromagnets, solid oxygen or geometrically frustrated magnets give some insight into the possibilities of this technique. To cite this article: I. Mirebeau, C. R. Physique 8 (2007).