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    يسر اللجنة العلمية بقسم الفيزياء دعوتكم لحضور الندوة العلمية السادسة في هذا الفصل. سيقدم الندوة مشكوراً د. مرزوق الشمري، الباحث في المركز الوطني لتقنية النانو بمدينة الملك عبدالعزيز للعلوم والتقنية.

عنوان الندوة هو:

“Spin-Based Electronics (Spintronics)”

(تجدون أدناه ملخص الندوة)

الزمان  : يوم الثلاثاء القادم 26 جمادى الأول 1436هـ الموافق 17 مارس 2015م من الساعة 10:45 إلى الساعة 11:30 صباحاً.

المكان : القاعة الكبرى 3001.
الحضور : كافة منسوبي الكلية، ونذكر بدعوة طلاب مشاريع التخرج.

مع تحيات اللجنة العلمية بقسم الفيزياء

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 Abstract:

Spin-based electronics technology forms the basis for information technology in the modern age by exploiting both the charge and spin of electrons in semiconductor devices through introducing a high concentration of magnetic elements into nonmagnetic semiconductors to make them ferromagnetic. When the power of the integrated circuits that exist today is switched off, the stored data in these circuits disappears while in magnetic circuits, the magnetic polarization does not leak over time.

There is a long history of research into magnetic semiconductor materials. Theoretical calculations of the Curie temperature (Tc) for a variety of wide bandgap semiconductor materials have been presented by Dietl. Dietl considered Mn-doped ZnO and GaN to be the two most promising materials for practical spintronic devices with room temperature ferromagnetism. This prediction inspired extensive research into magnetically doped oxides and nitrides. However, the major obstacle to the development of ZnO was the lack of reproducibility and the low-resistivity p-type ZnO.

The new generation materials are III-V based diluted semiconductors, such as In_(1-x)Mn_xAs and Ga_(1-x)Mn_xAs. In₂O₃ is one of the materials that Dietl did not consider in his calculations. Lately, several studies on doping In₂O₃ with small amounts of transition metals have been initialized. Room temperature intrinsic ferromagnetism, ferromagnetism from extrinsic transition metal clusters and no ferromagnetism at all have been reported. The controversy among these results led to a conclusion that the magnetic properties of transition metal doped In₂O₃ are very sensitive to the growth conditions. This talk will focus mainly on un-doped and doped In₂O₃ and will introduce a new method used to specify the source of ferromagnetism. This method shows whether the ferromagnetism is intrinsic due the incorporation of TM ions into the lattice of the host material or is due to secondary impurity phases. Such information cannot be provided by any other method.

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الندوة العلمية التالية:

31/03/2015: د. علي عيد.

العنوان:

“Unified field theory and its applications