X-RAY-DIFFRACTION STUDY ON THE FIRST-ORDER MAGNETIC PHASE-TRANSITION OF ERBIUM SINGLE-CRYSTAL

The time evolution of the first order magnetic phase transition of cycloidal-cone spiral magnetic structure in Er single crystal has been investigated by means of the X-ray diffraction technique. The phase transition has been observed through the discontinuous change of the c lattice parameter accompanying the transition. The appreciable time delay (incubation time) for the development of the stable magnetic phase has been detected systematically, which can be interpreted by the nucleation and growth theory including the effect of the long range strain force. Experimental results also indicate that the mosaicness of the single crystal sample may affect the kinetic behavior of the phase transition.