Suppression of the metal-insulator transition by magnetic field in (Pr1− y Y y )0.7Ca0.3CoO3 ( y  = 0.0625)

The (Pr1−yYy)0.7Ca0.3CoO3 compound (y = 0.0625, TMI-SS=40 K), at the lower limit for occurrence of the first-order metal-insulator (MI) and simultaneous spin-state (SS) transitions, has been studied using electrical resistivity and magnetization measurements in magnetic fields up to 17 T. The isothermal experiments demonstrate that the low-temperature insulating phase can be destabilized by an applied field and the metallic phase returns well below the transition temperature TMI-SS. The reverse process with decreasing field occurs with a significant hysteresis. The temperature scans taken at fixed magnetic fields reveal a parabolic-like decrease in TMI-SS with increasing field strength and a complete suppression of the MI-SS transition in fields above 9 T.