Mark formation mechanisms and R/W characteristics were investigated with a R/W tester and a polarized microscope for two kinds of exchange-coupled magneto-optical disk consistirlg of a reading layer and a writing layer. In one of the disks (a regularmode disk), recorded marks in the reading layer were transcribed to the writing layer, and vice versa in the other (an inverse-mode disk). For the regular-mode disks, the characteristics of the carrier levels in relataion to the writing power showed two stages, corresponding to ring domain and full domains. The ring domains appeared when the writing power was low, and were caused by the magnetics field near the Tc radius in the writing layer. The full domains appcared when the writig power was high, because the anisotropic field in the reading layer decreased sufficienty for this to occur.
For inverse-mode disks, only one stage was observed. This is because marks formed by the Curiepoint writing process in the writing layer, were transcribed to the reading layer.