The effect of Nb2O5 dopant on the structural and magnetic properties of MnZn-ferrites

Relation Between Firing Conditions Grain Boundary Structure and Magnetic Properties in Polycrystalline MnZn-Ferrites

“…• C, total power losses of 52 mW cm −3 that is very commendable and similar to the loss levels achieved with the usage of quite sophisticated doping mixtures [1,2]. Moreover the iron and manganese oxides used as raw materials in this work were of simple industrial grade.…”

“…[1][2][3][4][5]. Additives accumulate along the grain boundaries during the elevated stage or during the cooling stage of the firing process.…”

“…E-mail: zaspalis@cperi.certh.gr additive elements [7,8]. Occasionally, niobium [1,9], vanadium [2], bismuth [3,4] or their combinations [2] and others, have been also studied.…”

“…However, the great majority of the studies in the scientific literature concentrate on the effect of additives on the grain boundaries [1,8,9] or on the relation between grain boundary nature and magnetic properties [10,11]. In the patented literature the correlation between additives and magnetic properties is done directly [e.g.…”

Materials processing issues influencing the frequency stability of the initial magnetic permeability of MnZn ferrites

“…The rate of this diffusion process is controlled by the concentration of cation vacancies that, in turn, can be adjusted by the partial pressure of oxygen during sintering, through the equation The occupation of regular spinel lattice positions is not favored and ions such as Ca 2+ , Si 4+ , and Nb 5+ tend to leave the grains and segregate in pores or along the grain boundaries. 23,24 This enhanced dopant segregation that, under prolonged heating times, takes place in parallel with the process of grain growth process is believed as guide in the increased grain boundary resistivity that is observed despite the reduction in the grain boundary volume concentration, as shown in Figs. 6-8.…”