磁光记录技术是自有磁记录以来出现的最重要的一种新型数据存储技术。它集中了光存储和磁存储的优点，具有存储量大，非接触式读写和可擦写的特点。磁光薄膜是磁光记录信息的载体，这种薄膜必须与其他材料一起组成磁光盘方可记录信息。随着温度的变化，磁光记录薄膜的读出层的磁化方向也会发生改变。随温度升高读出层从平面磁化转变为垂直磁化,交换耦合两层薄膜具有中心孔探测磁超分辨的基本性能转变过程主要受饱和磁化强度(Ms)的影响,在GdFeCo的补偿温度附近,读出层的磁化强度较小，退磁场能也较小，在交换耦合的作用下,使读出层(GdFeCo)的磁化方向发生转变。

The magnetization transition caused by temperature changes has been investigated by the hysteresis loops and the Kerr rotation hysteresis loops. The results indicate that the magnetization direction of readout layer changes from in-plane to perpendicular with temperature increasing. The transition occurs mainly as a result of the changes in the saturation magnetization. When the temperature is increased to the compensation temperature,the saturation magnetization and the demagnetizing energy of the GdFeCo layer decreasｅ,with the exchange-coupled interaction ,the magnetization direction of readout layer changes from in-plane to perpendicular.then,we will study the mean field theory in the last part of the thesis.