ИСТИНА

We recently established that in iron garnet films the width of magnetic domains of the labyrinth domain structure decreases after adsorption of water molecules. The decrease of domain width of the films is explained by the reduction of effective magnetic anisotropy constant (K) and effective magnetic anisotropy field (Hk) due to the water molecules adsorption. Measurement of field Hk of iron garnet films in vacuum and in atmosphere of water vapor is carried out in this work. The value of Hk in iron garnet films was measured by magnetooptical method. The measured value of Hk is equal to 1.1 kOe in vacuum and 0.9 kOe in water vapor. The decrease of Hk is equal to about 20% in water vapor compared to vacuum. Using formula Hk=2К/Is, we reach the value of uniaxial magnetic anisotropy constant equal to К≈1100 erg/cm3 и 900 erg/cm3 in this two cases accordingly. Compressive deformation appears on the free surface of the iron garnet film due to the adsorption of water molecules. The tension induced by the water molecules adsorption is big enough and is less than the ultimate strength of iron garnets about by one order of magnitude.