arXiv subjects

V. Nietz

Publications and source records attributed to V. Nietz.

3 recordsLinked to original sources

arXiv2014

Equilibrium and overcritical solitons at a spin-flop phase transition

Taking into account the energy dissipation in the spin-flop phase transition induced by magnetic field in an antiferromagnet with uni-axial anisotropy, the following peculiarities of precessing ball solitons (PBS) are considered: a) the states of equilibrium solitons arising in the initial phase during the phase transition; b) the states of "overcritical PBS", existing outside the region of metastability. The "overcritical" PBS may originate during disintegration of the initial phase.

cond-mat.mtrl-sci↗

arXiv2014

A first order phase transition and self-organizing states in unidomain ferromagnet

Unidomain ferromagnet during the first order phase transition induced by a magnetic field directed along the axis of anisotropy, has been analyzed. It is shown that there is continuous spectrum of stationary states, which depends of relation between acting field value and the demagnetisation field. At addition action of the periodic field perpendicular to the main magnetic field with a certain frequency, there are dynamic equilibrium state, ie "self-organizing states" of ferromagnet, when the entropy increase connected with dissipation is compensated by the negative entropy flow due to the periodic field. It is shown that under these conditions, by varying the frequency of the periodic field, we can control the self-organising system, ie decrease or increase the system energy and, correspondingly, change the direction of magnetisation in ferromagnet.

cond-mat.mtrl-sci↗

arXiv2011

Precessing ball solitons as dissipative structures during a phase transition in a ferromagnet

Precessing ball solitons (PBS) in a ferromagnet during the first order phase transition induced by a magnetic field directed along the axis of anisotropy, while the action of the periodic field perpendicular to the main magnetic field, have been analyzed. Under this condition, the characteristics of arising equilibrium PBS's are uniquely determined by the frequency of the periodic field, but the solitons with other frequencies are impossible. It is shown that the equilibrium PBS's are essentially the "dissipative structures" that can arise in a metastable state.

cond-mat.stat-mech↗