Synthesis and characterization of magnesium ferrites material

مقدم أطروحة جامعية

Salma, Ghead Khalaf

مشرف أطروحة جامعية

Rida, Sabah Muhammad Ali

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم العلوم التطبيقية

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2012

الملخص الإنجليزي

In this work preparation NiZn and NiZnMg nano ferrites samples , using sol-gel auto combustion method at temperature about 2000C, then pelletized and sintered at different temperatures (1273, 1373 and 14730k).They have showed spinel structure and inherent properties of high electrical resistivity, low electrical losses and high density material.

Therefore, these ferrites have a potential candidate for high frequency applications The present work is study the electrical and structural properties of Ni1-xZnxFe2O4 and Ni0.7-yZn0.3MgyFe2O4, where (x=0, 0.1, 0.2, 0.3) and (y=0, 0.1, 0.2, 0.3) respectively, and shows effect of chemical composition on electrical, structural, and physical properties.

Crystalline ferrite Nano- powders and grains were successfully synthesized and the process has resulted in the formation of (19-22.6 nm) nano-sized particles, and (34-52 nm) nano-sized sintered grains.

Chemical phase analysis carried out by x-ray diffraction method confirms the formation of the expected ferrites structure, where lattice parameter and crystallite size increase but the x-ray density and porosity decreased when increasing the Zn content in NiZn ferrites.

Also the same behavior takes place when Mg content increases in NiZnMg-ferrites.

Resistivity of all samples have been measured at temperatures in The range of (300-540) K0 and found it decreases with the increasing of temperature like a semiconductor, and resistivity and temperature were used to calculate the activation energy.

Activation energy results showed decreases when increase the Zn content in NiZn ferrites.

Resistivity and activation energy both are increasing with high concentration of Mg ions.

The dielectric properties are measured using (LCR) meter in the frequency range of (100 Hz – 200 kHz), dielectric constant (εr'), the loss tangent (tanδ) and the loss factor (εr′′) are calculated from capacitance data, that the dielectric parameters decrease with increase of the frequency.

model.

This behavior is typical of ferrite materials as explained by Koop’s model.

Conductivity and dielectric loss were increased with the increase of the Zn content for NiZn ferrite, while conductivity and dielectric constant were decreased with increase the amount of Mg ion for NiZnMg -ferrite.

Found the resistivity of samples increase the amount of Mg batter than the models of sintered samples.

التخصصات الرئيسية

الهندسة الكهربائية

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-419009