Institutional Repository | Satya Wacana Christian University: Damping Dependence of Reyersal Magnetic Field on Co=Based Nano=Ferromagnetic with Thermal Activation
DAMPING DEPENDENCE OF REVERSAL MAGNETIC FIELD ON
CO-BASED NANO-FERROMAGNETIC WITH THERMAL
ACTIVATION
1)
Nadia Ananda Herianto, 2) Ferdy Semuel Rondonuwu, 2)Nur Aji Wibowo
Pendidikan Fisika, Fakultas Sains dan Matematika, Universitas Kristen Satya Wacana
2)
Fisika, Fakultas Sains dan Matematika, Universitas Kristen Satya Wacana
Jl. Diponegoro No.52-60, Salatiga (50711)
1)
[email protected]
ABSTRACT
Currently, hard disk development has used HAMR technology that applies heat to perpendicular
media until near Curie temperature, then cools it down to room temperature. The use of HAMR
technology is significantly influence by Gilbert damping constants. Damping affects the
magnetization reversal and coercivity field. Simulation is used to evaluate magnetization
reversal by completing Landau-Lifshitz-Gilbert explicit equation. A strong ferromagnetic cobalt
based material with size 50×50×20 nm3 is used which parameters are anisotropy materials
3.51×106 erg/cm3, magnetic saturation 5697.5 G, exchange constant 1×10-7 erg/cm, and various
Gilbert damping from 0.09 to 0.5. To observe the thermal effect, two schemes are used which
are Reduced Barrier Writing and Curie Point Writing. As a result, materials with high damping
is able to reverse the magnetizations faster and reduce the energy barrier. Moreover, it can lower
the minimum field to start the magnetizations reversal, threshold field, and probability rate. The
heating near Curie temperature has succeded in reducing the reversal field to 1/10 compared to
writing process in absence of thermal field.
Keywords: nanodot, Gilbert damping, HAMR, reversal field, Cobalt
CO-BASED NANO-FERROMAGNETIC WITH THERMAL
ACTIVATION
1)
Nadia Ananda Herianto, 2) Ferdy Semuel Rondonuwu, 2)Nur Aji Wibowo
Pendidikan Fisika, Fakultas Sains dan Matematika, Universitas Kristen Satya Wacana
2)
Fisika, Fakultas Sains dan Matematika, Universitas Kristen Satya Wacana
Jl. Diponegoro No.52-60, Salatiga (50711)
1)
[email protected]
ABSTRACT
Currently, hard disk development has used HAMR technology that applies heat to perpendicular
media until near Curie temperature, then cools it down to room temperature. The use of HAMR
technology is significantly influence by Gilbert damping constants. Damping affects the
magnetization reversal and coercivity field. Simulation is used to evaluate magnetization
reversal by completing Landau-Lifshitz-Gilbert explicit equation. A strong ferromagnetic cobalt
based material with size 50×50×20 nm3 is used which parameters are anisotropy materials
3.51×106 erg/cm3, magnetic saturation 5697.5 G, exchange constant 1×10-7 erg/cm, and various
Gilbert damping from 0.09 to 0.5. To observe the thermal effect, two schemes are used which
are Reduced Barrier Writing and Curie Point Writing. As a result, materials with high damping
is able to reverse the magnetizations faster and reduce the energy barrier. Moreover, it can lower
the minimum field to start the magnetizations reversal, threshold field, and probability rate. The
heating near Curie temperature has succeded in reducing the reversal field to 1/10 compared to
writing process in absence of thermal field.
Keywords: nanodot, Gilbert damping, HAMR, reversal field, Cobalt