Abstract:
Magnetic and electric properties of a single crystal of La0.7Ca0.3CoO3 have been experimentally studied. The system attains a ferromagnetic spontaneous moment below 170 K and exhibits a reentrant spin-glass phase below 100 K. In the ordered and the reentrant phases, the low-field magnetic properties are strongly direction dependent, showing considerably higher magnetization values perpendicular than parallel to the c axis. Magnetic relaxation experiments show that both the ferromagnetic and the reentrant spin-glass phases are nonequilibrium states, where the system exhibits magnetic aging characteristic of spin glasses and disordered and frustrated ferromagnets.