mahrous.r.ahmed

Mahrous R Ahmed

Assistant Professor -

Faculty of science

Address: Physics Department - Science Faculty - Sohag University - Egypt

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Mahrous R Ahmed is an assistant prof. in Physics Department, Science Faculty. My General field is Solid state Physics. My specific field is theoretical transition metals oxides. I have got my  Ph.D. from University of Sheffield, UK, in 2006. My work is basically in magnetic properties of metal oxides using Monte Carlo simulation with Potts and Ising model. Also I use many theoretical techniques in solving some Physical problems.


2018-09-06 18:40:27
تقويم الفصل الدراسي الأول للعام الجامعي 2018/2019
مواعيد كل الأسابيع الدراسية والإختبارات والعطلات في الفصل الدراسي الأول من العام الجامعي 2018/2019 Read more

2018-09-06 18:01:53 | Keywords Magneto caloric effect,
Electrical and magnetic transport in Strontium doped Europium Ferrimanganites
Eu0.65Sr0.35Fe_x_Mn1−_x_O3 (_x_=0.1, 0.3 and 0.5) has been prepared using a standard solid state reaction method. The under-investigation compounds is found to crystallize in a single-phase orthorhombic structure in the _P__bnm_ space group (62). The adiabatic polaron electronic transfer was obtained for all samples and the activation energy of _x_=0.1 sample is equal to 1.013 meV and slightly increase at _x_=0.3 ... Read more

2018-09-06 18:20:28 | Keywords Magnetoresistance, manganites,
Correlation of Magnetoresistance and Thermoelectric Power in La1-xLixMnOy Compounds
The temperature dependences of the thermoelectric power, TEP,(S) and magnetoresistance (MR) effect of La1-xLixMnOy (x= 0.05, 0.1, 0.15, 0.2 & 0.25 at%) fixed valence doped compounds were studied between 80K and 320K. X-ray powder diffraction (XRD) showed that the samples are single phase. We found the correlation of structures to the magnetoresistance (MR) and the thermoelectric power (S) which we ... Read more

2018-09-05 19:36:22 | Keywords quantum critical point, Landua theory,
Landau theory of compressible magnets near a quantum critical point
Landau theory is used to investigate the behavior of a metallic magnet driven toward a quantum critical point by the application of pressure. The observed dependence of the transitiontemperature with pressure is used to show that the coupling of the magnetic order to the lattice diverges as the quantum critical point is approached. This means that a first order transition ... Read more

2018-09-05 19:21:51 | Keywords MC simulation, manganites, Potts model,
Volume collapse in LaMnO 3 studied using an anisotropic Potts model
We have investigated the volume collapse occurring in LaMnO3 unit cell using the anisotropic Potts mode modified by two types of anisotropic interactions which has been used to study the behavior of the orbital-ordering configurations with temperature. The bond lengths are related to the occupation of the orbits. We have shown that the collapse is due to the change of ... Read more

2018-09-05 19:49:24 | Keywords Ising model,
Theory of magnetism with temporal disorder applied to magnetically doped ZnO
A dynamic model of the asymmetric Ising glass is presented: an Ising model with antiferromagnetbonds, −J">−J−J, and ferromagnetic bonds, +J">+J+J, with probabilities q">qq and 1−q">1−q1−q. The dynamics is introduced by changing the arrangement of the antiferromagnetic bonds after n">nn Monte Carlo steps but keeping the same value of q">qq and spin configuration. In the region where there is a second ... Read more

2018-10-08 09:20:28 | Electricity and magnetism
Task
الهدف من المقرر: * تعلم المفاهيم الأساسية لعلم الفيزياء * يتعرف الطالب على الكميات الفيزيائية ووحداتها * تزويد الطالب بقواعد أساسية لفهم أساسيات علم الكهرباء * تهيئة الطالب لإستنباط علاقات جديدة تخدم هذا العلم * تعريف الطالب طبيعة وخواص بعض الظواهر الكهربية وتمكينه من تفسيرها عمليا ونظريا * تهيئة الطالب للقراءة والاطلاع لمعرفة تخصصات فيزياء جديدة وتطبيقاتها Read more

2018-10-08 09:10:24 | Heat and Thermodynamics
Task
Introduction We will pay our attention to the study of thermodynamics, which involves situations in which the temperature or state (solid, liquid, gas) of a system changes due to energy transfers. As we shall see, thermodynamics is very successful in explaining the bulk properties of matter and the correlation between these properties and the mechanics of atoms and molecules. Read more

2018-10-01 19:28:54 | properties of matter
properties of matter
Exercises 1 - Distinguish between fundamental and derived units. Give examples. 2- Give the SI units in which the following physical quantities are measured : Frequency, magnetic flux, density, magnetic flux and inductance. 3- Derive the dimensions of: (1) surface tension (2) viscosity (3) gravitational constant and (4) moment of inertia. 4- Discuss the uses of dimensional analysis. 5- What ... Read more