A study of the structural and electrical properties of Ni1-x Cox Fe2O4 ferrites

Hind Mohammed Hasan

doi:10.30723/ijp.v12i25.306

Abstract

Ferrite with general formula Ni1-x Cox Fe2O4(where x=0.0.1,0.3,0.5,0.7, and 0.9), were prepared by standard ceramic technique. The main cubic spinel structure phase for all samples was confirmed by x-ray diffraction patterns. The lattice parameter results were (8.256-8.299 °A). Generally, x -ray density increased with the addition of Cobalt and showed value between (5.452-5.538gm/cm3). Atomic Force Microscopy (AFM) showed that the average grain size and surface roughness was decreasing with the increasing cobalt concentration. Scanning Electron Microscopy images show that grains had an irregular distribution and irregular shape. The A.C conductivity was found to increase with the frequency and the addition of Cobalt, D.C conductivity was found to increase with temperature due to decreases in resistivity. Dielectric constants were noticed to decrease with frequency and Co addition. The Hall coefficient was found to be positive. This demonstrates that the majority of charge carriers are p-type, suggesting that the mechanism of conduction is predominantly caused by hopping of holes.

Highlights

Ferrites form a very good class of electrical materials due to their high resistivity and low loss behavior, and have vast technological applications over a wide range of frequencies
A small change in lattice parameter may be related to the oxidation states and distribution of cations among tetrahedral (A) and octahedral (B) sites of the spinel structure, the probability that the Co+3 ions occupy the (A) sites of Fe+3 ions must be excluded, since the tetrahedral sites too small to be occupied by the large Co+3 ions which have large ionic radius
Standard ceramic technique was employed to prepare the cobalt nickel ferrites were at 900C°sintering temperature

Summary

Key words

Ferrite with general formula Ni1-x Cox Fe2O4(where x=0.0.1,0.3,0.5,0.7, and 0.9), were prepared by standard ceramic technique. X -ray density increased with the addition of Cobalt and showed value between (5.452-5.538gm/cm). Atomic Force Microscopy (AFM) showed that the average grain size and surface roughness was decreasing with the increasing cobalt concentration. The A.C conductivity was found to increase with the frequency and the addition of Cobalt, D.C conductivity was found to increase with temperature due to decreases in resistivity. Dielectric constants were noticed to decrease with frequency and Co addition. The Hall coefficient was found to be positive. This demonstrates that the majority of charge carriers are p-type, suggesting that the mechanism of conduction is predominantly caused by hopping of holes. ‫الخلاصة‬ x=0.0.1,0.3,0.5,0.7, ‫) حيث أن‬Ni1-x Cox Fe2O4 ) ‫تم تحضير أحد انواع الفيرايت ذو الصيغة التركيبية العامة‬ ‫ طور التركيب الرئيسي لكل العينات السبينل المكعب الذي‬.‫ استخدمت بالتحضير الطريقة القياسية في معالجه المساحيق‬,)0.9) ‫ بصوره عامه الكثافة المقاسة‬.)8.256-8.299 °A) ‫ ثابت الشبيكة الذي يتراوح قيمته بين‬.‫أكد بأنماط انحراف الأشعة السينية‬ ‫ أن استعمال مجهر القوة‬.)5.452-5.538gm/cm3) ‫ حيث تتراوح قيمتها بين‬Co ‫بالأشعة السينية تزداد مع زيادة تركيز‬ ‫ صورة المجهر الالكتروني بينت بأن‬.Co‫ يبين بأن معدل الحجم الحبيبي ومسامية السطح تقل كلما زاد تركيز‬AFM ‫الذري‬ ‫ التوصيلية المعتمدة‬.‫ وبزيادة التردد‬Co‫ التوصيلية الكهربائية تزداد بزيادة تركيز‬.‫الحبيبات غير منتظمة في التوزيع والشكل‬ .‫ والتردد‬Co ‫ تنخفض مع أضافه‬Ԑ2,Ԑ1 ‫ ثوابت العزل الكهربائية‬.‫على درجه الحرارة وجد بأنها تزداد بزيادة درجة الحرارة‬ ‫ تم الاقتراح بأن أمكانية التوصيل بالدرجة الأولى سببها قفز‬,p ‫معامل هول بين بأن حاملات الشحنة الأغلبية تكون من نوع‬

Introduction

Where D is the loss factor

Conclusion