Papers by Keyword: Anisotropy Field

Abstract: The Sr hexaferrites with chemical formula Sr_0.4La_0.3Ca_0.3Fe_11.85-xGa_xCo_0.15O₁₉ (x = 0.0 — 1.4) were manufactured by traditional ceramic method. The affect of Ga substitution on static magnetic properties and micromorphology of M-type Sr (SrM) hexaferrites have been presented in detail. In accordance with the experiment results, as Ga-substituted content x rises up from 0.0 to 1.4, all SrM hexaferrite samples are magnetoplumbite hexagonal structure. The difference between radius of Fe³⁺ and Ga³⁺ ions leads to the decrease of lattice constants. As the amount of Ga substitution x increases from 0.0 to 1.4, the 4πM_s and 4πM_r presents a trend of increasing, but the H_c shows the opposite trend. K₁ and H_a of all samples are higher than 2.5×10⁵ J/m³ and 21 kOe respectively, which manifests all samples possess the strong uniaxial anisotropy. The materials discussed in this paper possess huge potential in the application of high frequency self-biased microwave devices.

Abstract: The paper describes results of investigation on sputtered NiFe Films to determine the sputter deposition condition that could produce magnetic field sensors with the desired magnetic and magnetoresistive properties. The magnetic thin films materials used in such devices should have a low coercive force, a low anisotropy field and low magnetization dispersion, α50 with high magnetoresistance ratio. From the results presented, it is shown that that the most useful films for 82%Ni-Fe composition are produced at 200 °C-250 °C moderate substrate temperatures. It is also possible to specify the substrate bias potential and sputter gas pressure sputter deposition conditions under which the 82%Ni-Fe thin films may be employed for the production of magnetoresistine sensors with near optimum magnetic and magnetoresistive properties. The work also provide understanding of the effects on the magnetic properties of sputtered magnetic films that is very limited as current literature is almost entirely limited to evaporated magnetic films.

Abstract: The paper describes results of investigation on sputtered NiFe Films to determine the sputter deposition condition that could produce magnetic field sensors with the desired magnetic properties. The magnetic materials used in such devices should have a low coercive force, a low anisotropy field and a low magnetization dispersion, α50. .The results of systematic investigation of radio-frequency (RF) sputtered, RF biased, 82-18 % NiFe films showed (i) Improved Kobelev methods were applied to magneto-optic measurement techniques, suppress the magnetization ripples when subjected under the application of dc field. (ii) Anisotropy field results indicated an inverse trend with increasing substrate temperature (iii) the experimental measurements on magnetization dispersion relatively constant up to 200 °C with α50 approximately 1.2°, it then increases more sharply to about 3.5° at 400 °C substrate temperature. The work also provide understanding of the effects on the magnetic properties of sputtered magnetic films that is very limited as current literature is almost entirely limited to evaporated magnetic films.