Strong correlation effects and new phase transition at high pressure–low temperature in La0.5Ba0.5FeO3

Abstract The physical properties of La 0.5 Ba 0.5 FeO 3 perovskite have been investigated. The resistivity and magnetism change at around the charge disproportionation temperature. The ferromagnetic cluster-glass state appears when T 115 K . Under 5 kbar pressure a new phase transition at 5.5 K is found in the magnetization measurement. The transition temperature increases with the increase of the applied pressure. It is suggested that this transition is induced by the spin state transition from Fe 3 + ( t 2 g 3 ↑ e g 2 ↑ ) to Fe 3 + ( t 2 g 3 ↑ t 2 g 2 ↓ ) with the pressure increase.