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العنوان
Modelling of Ultrafast Laser in Inducing Magnetic Properties of Nanoparticles \
المؤلف
El-Said, Khaled Ahmed Ali.
هيئة الاعداد
باحث / خالد احمد علي السيد
مشرف / وسام الدين صلاح الدسن عبد العزيز
مشرف / جالة محمود العزب
الموضوع
Nanoparticles. Magnetic materials.
تاريخ النشر
2020.
عدد الصفحات
120, p.
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
الكيمياء
تاريخ الإجازة
1/1/2020
مكان الإجازة
جامعة القاهرة - المعهد القومى لعلوم الليزر - تطبيقات الليزر في القياسات والكيمياء الضوئية والزراعة
الفهرس
Only 14 pages are availabe for public view

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Abstract

The essence of magnetization is the angular momentum, arising from the electron spin. Circularly polarized pulses have strong temporary magnetic field pulses producing non thermal Opto-Magnetic effect via the inverse Faraday Effect. The mechanism of its excitation takes place via the stimulated Raman scattering. Ultrafast1 laser pulses opened a new area for magnetization dynamics time scale. This study is devoted to simulating the inverse Faraday Effect (Opto-Magnetic phenomena) in nanoparticles using ultrashort laser pulses and introducing a numerical model implemented by Matlab®. As for modelling the magnetic materials, the Finite Difference Time Domain (FDTD) is connected with Landau-Lifshitz-Gilbert equation. In the LLG equation, the local effective magnetic field is controlled by the time derivative of the magnetic moment in a micromagnetic cell. Maxwell’s field includes fields due to currents and magnetic sources, such as demagnetizing fields and Eddy current fields, by using FDTD-LLG computation techniques as the foot of the model represented here with a circular ultrashort laser pulse instead of the magnetic field in Landau-Lifshitz-Gilbert equation. In order to validate the results implemented in Matlab, the standard problem number four was used. It is one of the technical activities of the Micromagnetic Modeling Activity group from NIST. The computations implemented in Matlab are in good agreement with the standard problem number four results implemented in open source OOMMF (Object Oriented Micromagnetic-Framework.