Effect of the hydrostatic pressure on the coercive force of polycrystalline garnets

The effect of hydrostatic pressure (up to 1200 bar)on the reversible and irreversible magnetization mechanisms has been investigated in YIG samples. The relations between the reversible and irreversible parts of the magnetization, previously established for samples without defect inside the grains and no applied pressure, are shown to remain valid under pressure. The product of field parameters such as coercive force Hcby magnetization parameters such as susceptibility remains constant also in samples under pressure; this fact permits a single curve, pressure independent, to be obtained. The interpretation is based on a hypothesis of a variation with the applied pressure of the domain wall topography.