Neutron Diffraction and Reflectometry: A Review on Unique Role in Functional Magnetic Materials

Magnetic materials either in bulk or thin films are ubiquitous in our daily life. Technology based on magnetic materials range from chunk of bulk ferromagnet to thin film spintronics. In solid state bulk materials, information about its magnetic structure together with crystal structure is absolutely necessary to manipulate them in applications. Neutron diffraction is an important tool to determine atomic magnetic moments and its directions at the lattice site in the magnetic unit cell. It also investigates the type of magnetic ordering in conventional as well as new exotic materials. Magnetic thin films are engineered materials in which nanometer or sub-nanometer thickness scale films are grown. At such thicknesses nanoscale magnetic properties are fundamentally different than its bulk counterpart. Neutron reflectometry is a unique tool to investigate nano-magnetism in thin films. Moreover, in multilayer thin films generally used for spintronics, polarized neutron reflectometry is indispensable characterizing tool which investigates the magnetic properties in different layers and at the interfaces. In this chapter, we will introduce how neutron diffraction and reflectometry techniques play unique role in the investigation of magnetic structure and magnetic properties of functional bulk and nano-scale thin films.