Pressure effect in an itinerant-electron metamagnet at finite temperature

Taking the effect of spin fluctuations into account, the pressure effect on the metamagnetic transition (MT) in an itinerant-electron system is discussed at finite temperature. A characteristic relation between two phenomena, the susceptibility maximum and the MT, is also discussed under the pressure. It is shown that the MT disappears at a certain pressure. The critical pressure of the MT is shown to decrease with increasing temperature and becomes zero at a critical temperature. The pressure dependence of the critical temperature, at which the MT disappears, is obtained. Numerical calculations are carried out for an actual itinerant-electron metamagnet YCo ₂.