Static, dynamic and optical properties of bistable cylindrical domains

A film of the nominal composition of Ysub(1.4)Gdsub(0.6)BiFesub(3.8)Gasub(1.2)Osub(12), having a small thickness gradient of magnetization has been synthesized for the purpose of studying the properties of bistable cylindrical domains (BCD). The substrate was a Sm-Ga-garnet plate cut in the (100) plane. The static dynamic and optical properties of BCD have been investigated as well as the conditions for the transformation between two stable states of BCD. It has been experimentally found that such transformations do not occur in the quasistatic mode, but are only observed if short pulsed displacement fields are applied. Two models are proposed to explain these transformations. The high optical contrast between the BCD states in combination with the threshold nature of transformations between them allow to consider the BCD as a potential data carrier in magneto-optical devices. The maximum contrast observed was 70:1. The switch time may be as little as 10-7 s for a current of about 10 mA