Neutron research of hysteresis at a spin-flop transition induced by a pulsed magnetic field

Abstract

The character of a loop of a dynamic hysteresis that was obtained in diffraction research (Commun. JINR, P14-92-401, Dubna, 1992 (in Russian); Commun. JINR, P14-94-429, Dubna, 1994; J. Magn. Magn. Mater. 154 (1) (1996) 119) with a pulsed magnetic field on the IBR-2 pulsed reactor is analyzed. At H z = H zeq , on the forward front of a pulse the domains of the high-field phase that have been formed as the result of splitting π-solitons that divide the low-phase domains, begin to grow. The neutron intensity, which is approximately proportional to the size of new domains, reaches the maximum value when these domains fill the whole volume of a crystal, if the amplitude of pulses is sufficient for that. As a result, a steady magnetic structure of high-field domains divided by π-solitons (of another type) is formed. On the recession of a magnetic pulse, the reverse process occurs. In an example calculated near our experimental data, the process of complete phase reorganization takes place in 90 μs. Correspondingly, the mobility of domain walls equals about p w ≅0.65 cm O e − 1 s − 1 .