Low Temperature Physics: 45, 795 (2019); https://doi.org/10.1063/1.5111309
Effect of a low-frequency magnetic field on the properties of the main and additional echo signals in manganese ferrite
G.I. Mamniashvili, T.O. Gegechkori
Тбилисский государственный университет им. И. Джавахишвили, Институт физики им. Э. Андроникашвили, ул. Тамарашвили, 6, г. Тбилиси, 0177, Грузия
Тбилисский государственный университет им. И. Джавахишвили, пр. Чавчавадзе, 1, г. Тбилиси, 0179, Грузия
Received February 13, 2019 г., published online May 28, 2019
The features of the formation of additional echo signals, the formation mechanism of which is different from the classical Hahn’s mechanism, are experimentally investigated in the MnхFe2–хO4 system in the region of helium temperatures. It was found that in the MnхFe2–хO4 system, the maximum intensity of the additional echo corresponds to ferrite with the minimum magnetocrystalline anisotropy. The application of the low-frequency magnetic field method has led to the discovery of the effect of correlating changes in the signals of the main and additional echo in manganese ferrite at helium temperatures, which indicates that they have an inter-boundary origin in contradiction with the well-known interpretations of the NMR spectrum in manganese ferrite. The observed effect may be due to the process of displacement of domain walls under the influence of a low-frequency magnetic field relative to the state corresponding to the minimum of the potential well given by its pinning center.
Key words: NMR echo, low-frequency field, magnetic videopulse, dynamic frequency shift, domain wall.