Magnetization in insulating phases of Ti4+-doped SrFeO3−δ

Abstract

SrFeO 3 − δ belongs to the Ruddlesden-Popper class of systems exhibiting interesting electronic and magnetic properties. Ti4+-doped, oxygen-deficient SrFeO3−δ(SrFexTi1−xO3−δ; x=0.9 and 0.7) samples show canted antiferromagnetic spin ordering, in contrast to the undoped sample (x=1) which is known to exhibit a metallic behavior with a helical spin arrangement. ac susceptibility χac (f,T) at 10⩽T⩽300K shows a frequency (100Hz⩽f⩽10kHz)-dependent temperature maximum, reminiscent of a spin-glass behavior. Increasing the Ti4+ content reduces the irreversibility, indicating a decrease in the frustration, which results in a diluted helical spin structure. Hysteresis loops can be associated with a gradual reorientation of spins in the field direction, indicating a canted type of spin arrangement.