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.
Measuring Sheet Resistances of Dielectrics Using Co‐Planar Hydrogel Electrochemical Cells with Practical Applications to Characterize the Protective Quality of Paints on Sculptures
Electrical properties of thin dielectric films at the solid-liquid phase boundary are an important performance characteristic of many devices, coatings and sensors. In this paper, co-polymeric hydrogels of polyacrylic acid co-sulfonic acid, swollen with a salt solution to act as the solid electrolyte, were used to assess interfaces using electrochemical impedance spectroscopy (EIS) in a co-planar geometry. Silane-modified glasses were characterized by the co-planar hydrogel EIS cell and found to be distinguishable based on their surface monolayer chemistry. EIS measurements were also made on primed and painted metal substrates, using both test panels and an outdoor sculpture, Tony Smith's Stinger. The panels were then exposed to accelerated and outdoor weathering and showed degradation on the surface paint layers, which was observable electrochemically using EIS and confirmed visually by SEM. Electrochemical spectral features were compared between data from a standard paint-test cell versus this co-planar hydrogel cell; both cell types were able to measure coating capacitance, providing useful information about the condition of the bulk coating. Yet, sheet resistance (Rs) was a spectral feature seen only by the co-planar hydrogel cell. Thus, it can be concluded that the use of such co-planar hydrogel cells can provide an earlier warning sign to coating degradation and such cells provide a new type of spectral information that is not assessable by the standard geometry.