Charge and magnetic order in novel layered double perovskites LnBaFe2O6 (Ln = Nd, Tb, Y) containing unusually high and mixed valence Fe3.5+

Newly synthesised A-site layer-ordered double perovskites LnBaFe2O6 containing unusually high and mixed valence Fe3.5+ were found to show complicated and successive charge and magnetic transitions. To reveal the natures of the transitions, we propose temperature-dependent neutron diffraction experiments at the WISH diffractometer to clarify the charge and spin orders. The expected results will give us new insights in correlation of charge, spin, and lattice degrees of freedom of the unusually high valence transition-metal oxide systems.