Description of giant changes of domain sizes in ultrathin magnetic films

Metallic ultrathin magnetic layers can exhibit either the thickness or field-induced reorientation phase transitions (RPT - the transition from the easy magnetization axis to the easy plane). Results of both analytical analysis and simulation studies of magnetization distribution evolution approaching the RPT are presented. The transition from Kittel-like domain structure state into in-plane magnetization monodomain state undergoes through the sinusoidal domain structure. Few orders of magnitude decrease of domain size (down to nanometer scaled domains) is obtained approaching the RPT