Magnetic State in GdMg at High Pressure

The pressure-temperature magnetic phase diagram of GdMg has been determined by measurements of ac magnetic susceptibility and magnetization at high pressures. A new pressure-induced antiferromagnetic phase with a metamagnetic character appears above 7 kbar and a canted phase which appears even at ambient pressure vanishes at about 17 kbar. Pressure-sensitive conduction band character has been briefly discussed in connection with the s - f exchange interaction.