The birth of time‐of‐flight (TOF) neutron powder diffraction at pulsed neutron source (invited)

Behind every improvement there is a story. The early history of the TOF neutron powder diffraction technique is presented. Successes and problems in the application of this technique in material science are reported. Powder diffraction technique is very useful when materials, in a single crystal form, reveal complicated electric and magnetic domain structures. Finding and describing the magnetic structure of multiferroics is the great success of ultra-high resolution TOF neutron diffraction. This unique role of the TOF method in discovery of the modulated magnetic structure of BiFeO3 is presented. To date, the TOF powder neutron diffraction technique gives the richest information on the long period modulated magnetic structure of BiFeO3 and its solid solutions. Determination of magnetic moment direction in a crystal lattice is the unique area of application of the TOF technique. The current status and perspectives of the application of the TOF neutron powder diffraction technique in material science are presented in the review.