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мікромагнітний розподіл
коерцитивна сила
петля магнітного гістерезису
micromagnetic distribution
coercive force
magnetic hysteresis loop

Запропоновано методику, та розроблено комп’ютерну модель, для дослідження поведінки магнітних наноматеріалів під впливом зовнішніх магнітних полів. Побудовано графіки розподілу вектора намагніченості. Проведено аналіз отриманих результатів згідно мікромагнетичної теорії. Отримано залежності основних магнітних характеристик феромагнетика. Отримано теоретичний розрахунок петлі магнітного гістерезису для ультратонких плівок, без врахування впливу струмів Фуко.
Computer design of distributing the magnetized ferromagnetic gives the possibility to predict the behavior of material in variable magnetic fields. The software in the environment of MatLab was developed in this paper for the design of micromagnetic distribution on the surface of one layer film. The mathematical model was realized on the basis of discretely dipole approximation taking advantage of the Monte-Carlo method. The crystalline barn of F3+ atom was chosen as discretely environment. The total inside energy of dipole consists of exchangeable interrelation energy, dipole energy – dipole interrelation, energy of surface magnetical anisotropy and the external energy of magnetic field. In the realized model the surface of the film was distributed into n-identical parts, in which the modules of magnetical moments are considered to be similar, and the total film magnetization depends on mutual location of each of moments. Calculation was carried out in polar system of coordinate, as in one-layer films the magnetic moment and vector of magnetic anisotropy can be change a in one plane. According to the results of calculation vector fields of magnetization distribution were built for different values of tension and dependence of the sample magnetization on outside magnetic field. It was shown in the paper that sharp magnetization at small enough values of outside field takes place due to the reorientation of magnetical moments domens, the direction of which is close to the direction of the outside field. Further increase of magnetization takes place due to the increase of the domens area. Basing on the behavior of the sample the estimation of magnetization saturation value and the power of coercive force was carried out. To build the loops of magnetic hysteresis the model on the basis of arctangents that gives the results close to the experimental ones was used. The built loop does not represent the total expenditures while overmagnetizing, as the expenditures for vortex currents were not taken into account.