The interesting functions of additives in NiZn-ferrite
introduction Additives play a quite significant roll in microwave ferrites. Proper sorts and quantities of additives can improve aany important characteristics of materials. In this paper, two kinds of additives,NW and cd). are discxlssed about their effects on tk remanent ratios R of NiZn ferrites used in milliaeter-wave band. Both of them can enhance R efficiently so that they are beneficial to latching device applications. The mechanism is discussed qualitativeiy.At the same tile,scnoe interesting attendent phenomena are rqnrted. ExDeriments The specimens were prepared with wnventional ceramic process with the composition as follows: NILCo. Zb., CU, Bim Nb. & Fel.s 0, (1) The B-Hloops were traced with a YEW W e 1 3251 Auto Tracer. The raoanent ratics +R/R were read off the loops of sa!41ples,whose mercive forces were around 80 A/m (1 Ce), with the magnetizing field H,-3Z@A/n(40 Oe).B and B, are residual and saturation inductions,respectively.
Magnetostriction of Ni-Zn ferrites containing cobalt
Abstract The influence of a small cobalt content on the magnetostriction of Ni-Zn ferrites has been investigated and is discussed. It is shown that, as in the case of a magnetocrystalline anisotropy, the value of λ s may in this case be quite different from that expected. The results prove that, in spite of common opinion, there are no “piezomagnetic obstacles” to introducing Co ions into Ni-Zn ferrites, when the diminishing of their magnetic loss factor in high frequency range is needed.
Effect of MoO3 Addition on the Grain Growth Kinetics of a Manganese Zinc Ferrite
The effect of MoO3 addition on the grain growth and densification kinetics of a high permeability manganese zinc ferrite was studied. Grain growth in the presence of a small amount of MoO3 occurs in two main stages characterized by a faster rate of grain growth accompanied by rapid densification and pore coalescence in the first stage, when the MoO3 is present as a liquid phase along the grain boundaries, and comparatively slower rates of grain growth and densification than those for the basic composition in the second stage, when MoO3 evaporates from the matrix. The activation energies for grain growth in these stages suggested that surface and volume diffusion mechanisms were operating in the first and second stages respectively.