INVESTIGADORES
BAB Marisa Alejandra
congresos y reuniones científicas
Título:
Modeling the interfaces dynamics between magnetic domains obtained by Heat-assited magnetization reversal in high coercitive ultrathin films
Autor/es:
BAB, MARISA ALEJANDRA; G P SARACCO; S. M. COTES
Lugar:
Córdoba
Reunión:
Congreso; XIII Latin American Workshop on Nonlinear Phenomena; 2013
Institución organizadora:
Universidad Nacional de Córdoba
Resumen:
In
order to develop high-density information recording devices with storage densities
above terabits/cm2, it is necessary to simultaneously achieve high
thermal stability at operation temperatures and high recording rates. However,
for area data density above terabits/cm2 the size of the bit
approaches the superparamagnetic limit where the thermal fluctuations degrade
the stability of the magnetization. Moreover, actual standard requirements for
applications imply that a 95% of the bit magnetization must remain over a
period of ten years and the possibility of subnanosecond magnetization switching
times. Perpendicularly magnetized ultrathin films made of high coercivity
materials are used with the intention of overcome the superparamagnetic limit,
in combination with heat-assisted magnetization reversal (HAMR) to perform a
suitable recording. The HAMR method is used in order to reduce temporarily the high
coercitive field, during the writing process, by a localized heating above the
critical temperature, such as the obtained with a laser pulse. Recently, a
single model of the HAMR process over ultrathin films with strong anisotropy
has been suggested [Phys Rev. B 84, 094431 (2011)], which is based in the ferromagnetic
Ising Model and where the laser pulse is emulated by time-dependent Gaussian temperature
profile. This model allowed to study the kinetics of nucleation and growth of
the magnetic domains by means of Monte Carlo simulations, and to determine the dynamic
spinodal corresponding to the crossover between multidroplet and single droplet
nucleation regimes. In this work, we implemented
a code with a variant of the described model where the external magnetic field
and the time-dependent temperature profile are synchronized, and then simulated
the magnetization reversal process. The
interface dynamics and the thermal stability of the domains obtained by HAMR were
investigated as a function of the strength of the magnetic field and the
elapsed time of the temperature profile, for different system sizes.