Dynamic exchange effect induced multi-state magnetic phase diagram in manganese oxide Pr1-Ca MnO3

The crystal structure and magnetic properties of Pr 1- x Ca x MnO 3 (PCMO) were investigated systematically. It is shown that the symmetry of the structure is improved with the increase of Ca 2+ ions. At the same time, the distortion of the MnO 6 octahedron is reduced due to the weakening of the Jahn-Teller (J-T) effect in the system. Magnetic characterization shows that the original ferromagnetic (FM) at the low doping range ( x = 0.2, 0.3) begins to appear antiferromagnetic (AFM) at the half doping range ( x = 0.4, 0.5). Such magnetic transition is derived from the dynamic competition between the double exchange (DE) effect and the super exchange (SE) effect. These two exchange effects are significantly affected by structural distortions and charge-ordered (CO) phases. The coexistence and transition of multiple magnetic states embody complex internal competition in PCMO. Analysis of its intrinsic mechanism is helpful for designing spintronic devices.