Magnetotransport Irreversibility in Single Crystalline La0.18Pr0.40Ca0.42MnO3 Thin Films

Magnetotransport irreversibility in single crystalline La0.18Pr0.40Ca0.42MnO3 thin films is probed with respect to intrinsic electronic phase separation (IEPS). Temperature-dependent magnetization and resistivity measurements show that (i) the high temperature non-hysteretic regime is dominated by the antiferromagnetic insulator (AFMI) and the charge ordered (CO) phases; (ii) at intermediate temperatures hysteretic regime is akin to a spin liquid; and (iii) the glass transition occurs at temperature T-g below which the spin liquid freezes. The suppression of the ferromagnetic and insulator-metal transitions (T-C and T-IM) during cooling confirms supercooled magnetic liquid. Magnetic field-dependent resistivity (rho-H) measured during cooling and warming highlights the differences in the spin-ordered structures through (i) reversible behavior at T T-IM (warming). The present study demonstrates that the scaling of area between the isothermal cooling and warming cycle rho-H curves with temperature mimics the rho-T behavior and hence also reflects the insulator-metal transition. The observed irreversibility and the area scaling in the different spin regimes have been explained in terms of the intrinsic electronic phase separation