Тип публикации: статья из журнала
Год издания: 2020
Идентификатор DOI: 10.1134/S1063783420090255
Ключевые слова: cofe(2)o(4)nanoparticles, antiferromagnetic nio nanoparticles, dynamic magnetization switching, coercive force, cofe2o4 nanoparticles, dynamic magnetization switchingthis work was supported by the russian foundation for basic research, the government of the krasnoyarsk region, and the krasnoyarsk regional foundation for science, project no. 18-42-240012: “magnetization switching of magnetic nanoparticles in strong pulsed magnetic fields is a new approach to studying the dynamic effects related to the processes of magnetization of magnetic nanoparticles.”
Аннотация: In antiferromagnetic (AFM) nanoparticles, an additional ferromagnetic phase forms and leads to the appearance in AFM nanoparticles of a noncompensated magnetic moment and the magnetic properties typical of common FM nanoparticles. In this work, to reveal the regularities and differences of the dynamic magnetization switching in FM Показать полностьюand AFM nanoparticles, the typical representatives of such materials are studied: CoFe(2)O(4)and NiO nanoparticles with average sizes 6 and 8 nm, respectively. The high fields of the irreversible behavior of the magnetizations of these samples determine the necessity of using strong pulsed fields (amplitude to 130 kOe) to eliminate the effect of the partial hysteresis loop when studying the dynamic magnetic hysteresis. For both types of the samples, coercive forceH(C)at the dynamic magnetization switching is markedly higher thanH(C)at quasi-static conditions.H(C)increases as the pulse duration tau(P)decreases and the maximum applied fieldH(0)increases. The dependence ofH(C)on field variation ratedH/dt=H-0/2 tau(P)is a unambiguous function for CoFe(2)O(4)nanoparticles, and it is precisely such a behavior is expected from a system of single-domain FM nanoparticles. At the same time, for AFM NiO nanoparticles, the coercive force is no longer an unambiguous function ofdH/dt, and the value of applied fieldH(0)influences more substantially. Such a difference in the behaviors of FM and AFM nanoparticles is caused by the interaction of the FM subsystem and the AFM "core" inside AFM nanoparticles. This circumstance should be taken into account when developing the theory of dynamic hysteresis of the AFM nanoparticles and also to take into account their practical application.
Журнал: PHYSICS OF THE SOLID STATE
Выпуск журнала: Vol. 62, Is. 9
Номера страниц: 1518-1524
ISSN журнала: 10637834
Место издания: MOSCOW
Издатель: PLEIADES PUBLISHING INC