Effect of M 2+ substitution on properties of the system Ni x Zn 1-x-y M y Fe 2 O 4 1 Nahedh H. Alwash, 2 Asst. Prof. Hadey K. Mohamad, 3 Prof. M.H. Almaamori 1,2 Department of Physics- College of Science, Al-Muthanna university 3 College of Materials Engineering Babylon University E-mail addresses: hadeyk2002@yahoo.com; nh.alwash@yahoo.com Keywords: Co-precipitation; Permittivity; Initial permeability; Magnetic hysteresis loops of Ni x Zn 1-x-y M y Fe 2 O 4 ABSTRACT. The four types of ferrites have been prepared by co-precipitation technique(Ni Zn Fe 2 O 4 ,Mg Fe 2 O 4 ,Mn Fe 2 O 4, Cd Fe 2 O 4 ). The prepared ferrites were sintered at 800C˚. Then using the these types of ferrite to prepared the final Synthesis Ni x Zn 1-x-y M y Fe 2 O 4 were M 2+ =(Mg,Mn,Cd) with (X=0.3),(Y=0.4) to be six samples halve of these as pressed pellets (12.3 mm diameter, 5-4mm thickness)and later halve as triodes (R in =9.85mm,R out =19.4mm). All of them were sintered at (1100 C) for (2 hr). (XRD) Technique was used to study the structure of matrix Ni x Zn 1-x-y M y Fe 2 O 4 , the apparent density , and porosity were calculated, The electrical characteristics for these samples included the measure of A.C current as the dielectric constant was calculated (έ ) ,loses factor(tan δ) was measured at the same frequency range(20Hz - 3MHz)to calculate the imaginary part of dielectric constant and also the magnetic properties was measured by the same equipment, (initial permeability μ ) was calculate after measuring the inductors(L), the VSM Technique was used to study hysterics lope behavior of these samples. 1. INTRODUCTION Spinal ferrite possess unique electrical and magnetic properties for wide range of technological application .the general formula of spinal ferrite is represented by AB 2 O 4 and it possesses 64 tetrahedral sites (A-sites ) and 32 octahedral sites (B-sites )[1]. Manganese-Zinc Ferrites are the most common, and used in many more applications than the nickel-zinc ferrites. The MnZn category a large variety of materials is possible .The material selection is mainly a function of the application that needs to be accommodated. The application dictates the desirable material characteristics, which in turn determines the chemical composition of the ferrite material. Manganese zinc ferrite is primarily used for frequencies less than 2MHz . But Nickel-Zinc Ferrites this class of soft ferrites is characterized by its high material resistivity several orders of magnitude higher than MnZn ferrites. Because of its high resistivity Ni Zn ferrite is the material of choice for operating from l-2 MHz to several hundred megahertz. Also magnesioferrite (MgFe 2 O 4 ) is one of the most interesting, because, due to its small magneto crystalline an isotropy .To cover such a wide frequency range and different applications, a large number of nickel-zinc materials have been developed over the years by mixing together, also Ni-Zn polycrystalline ferrites(NZF)are low-cost materials that are attractive for microwave device applications ,with spinel structure has a promising potential as high performance microwave devices owing to its high resistivity, mechanical hardness, high Curie temperature, chemical stability, and soft magnetic properties at high frequency. It is well known that the intrinsic parameters of these ferrites depend on the composition, Properties of ferrites are known to be sensitive to the processing technique ]2[. The tailoring grain structure with electrical characterization such as that electrical resistivity decreasing with increasing of sintering temperature[3]. All these ferrites have been widely used in electronic applications such as transformers, choke coils, noise filters, and recording heads. By introduction of a relatively small amount of foreign ions, an important modification of both structure and magnetic properties can be obtained [3,4]. The electrical resistivity of ferrite at room temperature depending upon the chemical composition which lies between about 10 3 - 10 8 Ohm- cm. Low resistivity due to hopping of bonding electrons are caused by the simultaneous presence of International Letters of Chemistry, Physics and Astronomy Online: 2016-01-04 ISSN: 2299-3843, Vol. 63, pp 42-48 doi:10.18052/www.scipress.com/ILCPA.63.42 CC BY 4.0. Published by SciPress Ltd, Switzerland, 2016 This paper is an open access paper published under the terms and conditions of the Creative Commons Attribution license (CC BY) (https://creativecommons.org/licenses/by/4.0)