paper

Role of Magnetic Exchange Energy on Charge Ordering in RSFO (R=La, Pr, and Nd)

arXiv:1107.5507 · doi:10.1103/PhysRevB.84.224115

Abstract

Inelastic neutron scattering is applied to study the role of magnetism in stabilizing the charge ordered state in \emph{R} $_{1/3}$ Sr $_{2/3}$ FeO $_{3}$ (\emph{R}SFO) (\emph{R} = La, Pr, and Nd). The ratio of the ferromagnetic exchange energy (J $_{F}$ ) and antiferromagnetic exchange energy (J $_{A F}$ ), |J $_{F}$ /J $_{A F} ∣, i s ak ey in d i c a t or o f t h es t abi l i t y o f t h ec ha r g eor d er e d an d an t i f er r o ma g n e t i cor d er e d s t a t e . T hi sr a t i o i so b t ain e df r o m t h es p in w a v es p ec t r u mb y in e l a s t i c n e u t r o n sc a tt er in g an d i ss u f f i c i e n tl y l a r g e t os ug g es tt ha tt h e ma g n e t i ce x c han g ee n er g y a l o n ec an s t abi l i z e t h ec ha r g eor d er e d s t a t e in L a$ _{1/3} $S r$ _{2/3} $F e O$ _{3} $an d P r$ _{1/3} $S r$ _{2/3} $F e O$ _{3} $. T h ee x c han g er a t i o d ecr e a ses f r o m L a$ _{1/3} $S r$ _{2/3} $F e O$ _{3} $t o N d 1$ _{1/3} $S r$ _{2/3} $F e O$ _{3}$ which indicates a gradual destabilization of the magnetic exchange mechanism for charge ordering in correspondence with the observed reduction in the ordering temperature.