Magnetic Behavior of Polycrystalline Gadolinium Subjected to a Magneto-Thermal Protocol

Magneto-thermal (M-T) hysteresis is studied in polycrystalline gadolinium (Gd). The change of the sign of the first anisotropy constant leads to easy cones of magnetization below the spin-reorientation temperature ( $T_{\mathrm {SR}} = 250$ K). Cooling a polycrystalline Gd sample in a magnetic field through the spin-reorientation temperature creates magnetic structures which persist to temperatures close to the Curie temperature, if these structures are not erased by going to fields larger than the cooling field. An M-T protocol is applied to give some systematics to these complex processes.