Spontaneous and Magnetic-Field-Induced Spin-Reorientation First-Order Phase Transitions in Rco_5-Type Compounds

摘要

It is shown that, based on the temperature dependence of magnetization measured using free spherical hexagonal single-crystal samples, one can determine the nature of a spontaneous spin-reorientation transition. In the case of first-order phase transitions, deep minima in the magnetization are observed at the transition temperatures, whereas no such minima occur if the transitions are of second order. In some (Nd,Y)Co_5 and (Nd,Sm)Co_5 alloys, both spontaneous and magnetic-field-induced spin-reorientation transitions caused by specific magnetoanisotropic properties of the neodymium subsystem are observed.