相关论文: Multilevel model for magnetic deflagration in nano…
The reversal of spins in a magnetic material as they relax toward equilibrium is accompanied by the release of Zeeman energy which can lead to accelerated spin relaxation and the formation of a well-defined self-sustained propagating…
Anisotropy effects for spin avalanches in crystals of nanomagnets are studied theoretically with the external magnetic field applied at an arbitrary angle to the easy axis. Starting with the Hamiltonian for a single nanomagnet in the…
The magnetization of the prototypical molecular magnet Mn12-acetate exhibits a series of sharp steps at low temperatures due to quantum tunneling at specific resonant values of magnetic field applied along the easy c-axis. An abrupt…
Theory of magnetic deflagration (avalanches) in crystals of molecular magnets has been developed. The phenomenon resembles the burning of a chemical substance, with the Zeeman energy playing the role of the chemical energy. Non-destructive…
The energy released in a magnetic material by reversing spins as they relax toward equilibrium can lead to a dynamical instability that ignites self-sustained rapid relaxation along a deflagration front that propagates at a constant…
Recent experiments (Decelle et al., Phys. Rev. Lett. 102, 027203 (2009)) discovered an ultra-fast regime of spin avalanches in crystals of magnetic magnets, which was three orders of magnitude faster than the traditionally studied magnetic…
For the first time, the morphology and dynamics of spin avalanches in Mn12-Acetate crystals using magneto-optical imaging has been explored. We observe an inhomogeneous relaxation of the magnetization, the spins reversing first at one edge…
Decay of metastable states in molecular magnets (MM) leads to energy release that results in temperature increase that, in turn, positively affects the decay rate. This is the mechanism of recently discovered magnetic deflagration that is…
Theory of magnetic deflagration taking into account dipolar-controlled spin tunneling has been applied to the realistic model of molecular magnet Mn_12 Ac. At small transverse field, the front speed v has tunneling maxima on the bias field…
The stability of a magnetic deflagration front in a collection of molecular magnets, such as Mn_12-acetate, is considered. It is demonstrated that stationary deflagration is unstable with respect to one-dimensional perturbations if the…
We obtain a fundamental instability of the magnetization-switching fronts in super-paramagnetic and ferromagnetic materials such as crystals of nanomagnets, ferromagnetic nanowires, and systems of quantum dots with large spin. We develop…
Local time-resolved measurements of fast reversal of the magnetization of single crystals of Mn12-acetate indicate that the magnetization avalanche spreads as a narrow interface that propagates through the crystal at a constant velocity…
Despite extensive researches on manganites owing to widespread use in modern electronics, this class of metal oxides does not cease to surprise with its unique properties and new phenomena. Here we have studied structural and magnetic…
Experimentally detected ultrafast spin-avalanches spreading in crystals of molecular (nano)magnets (Decelle et al., Phys. Rev. Lett. 102, 027203 (2009)), have been recently explained in terms of magnetic detonation (Modestov et al., Phys.…
Using micron-sized Hall sensor arrays to obtain time-resolved measurements of the local magnetization, we report a systematic study in the molecular magnet Mn$_{12}$-acetate of magnetic avalanches controllably triggered in different fixed…
We measure the temperature, magnetic-field, and current dependence for the switching of nanomagnets by a spin-polarized current. Depending on current bias, switching can occur between either two static magnetic states or a static state and…
The reversal of the magnetization of crystals of molecular magnets that have a large spin and high anisotropy barrier generally proceeds below the blocking temperature by quantum tunneling. This is manifested as a series of controlled steps…
The magnetic instability at the front of the spin avalanche in a crystal of molecular magnets is considered. This phenomenon reveals similar features with the Darrieus-Landau instability, inherent to classical combustion flame fronts. The…
We use neutron diffraction to probe the magnetization components of a crystal of Mn12 single-molecule magnets. Each of these molecules behaves, at low temperatures, as a nanomagnet with spin S = 10 and strong anisotropy along the…
Combination of the thermal effet in magnetic deflagration with resonance spin tunneling controlled by the dipole-dipole interaction in molecular magnets leads to the increase of the deflagration speed in the dipolar window near tunneling…