High-temperature superconductors, as seen through the eyes of neutrons

Neutron scattering is proved to be a vital probe in unveiling the magnetic properties of high temperature superconductors. Detailed information about the energy and momentum dependence of the magnetic dynamics of high temperature superconductors have been obtained directly by this technique. Over the past decade by improving the crystal growth methods, large and high quality single crystals of high temperature superconductors, which are essential for a neutron scattering experiment, have become available. The results of neutron scattering measurements on such crystals have considerably enhanced our understanding of the magnetism in high temperature superconductors both in the superconducting and normal states. In this review, the neutron scattering results on two main high temperature superconductors families, La2-xSrxCuO4 and YBa2CuO3O6+x, are considered with an emphasis on the most prominent properties of these materials that are now widely accepted. These include the presence of strong antiferromagnetic fluctuations even in optimally doped region of the phase diagram. neutron resonance peak that scales with superconducting transition temperature, T,, incommensurate magnetic fluctuations (stripes), and a pseudo gap in the normal state of under doped materials