Magnetic Material Parameters Research Articles

Effects of finite anisotropy parameter Q in the determination of magnetic bubble material parameters

Improved formulas are obtained to provide more accurate determination of magnetic bubble material parameters such as material length (l) and saturation magnetization (M_{s}) based on the measurements of domain stripe width and bubble collapse field. The improvement takes into consideration the effects of finite uniaxial anisotropy parameter (Q) in the formulas. These improved formulas are based on the numerical results obtained from micromagnetic domain calculations of periodic stripes and of an isolated axisymmetric bubble.

Primary transducers for measurement of the parameters of magnetic materials at hf

Primary transducers for measurement of the parameters of magnetic materials at hf

Determination of microwave properties of semiconductors using spherical cavities

The paper proposes a method for measuring complex permittivity and permeability of small semiconductor samples using two spherical microwave cavities. When a spherical sample is placed at the centre of the cavity the electromagnetic fields can be solved exactly, except for unimportant amplitude coefficients in the whole interior of the resonator. Consequently the complex resonant frequencies of different cavity modes have analytic solutions in terms of electric and magnetic material parameters of the sample. The parameters can then be calculated from the measured resonant frequencies and quality factors of two spherical cavities; further more the accuracy of the results is limited only by the accuracy of the measurements. In addition, the exact solutions give an opportunity to check the validity of the ordinarily used cavity perturbation theories.

Magnetic measurements for digital magnetic recording

Common engineering magnetic measurements used in the definition and application of digital recording media are defined along with their relationships to basic magnetic material parameters. The effects of the variation of magnetic material parameters on digital recording performance are discussed. Descriptions are given of the operation and use of φ-H meters and vibrating sample magnetometers. Sample shape and preparation considerations are included.

Cylindrical Magnetic Domain Epitaxial Film Characterization: Device and Growth Implications

The effects of magnetic material parameter variations on the operating bias-field and bubble diameter ranges of magnetic bubble devices are discussed theoretically. In addition, experimental measurements are reported of spatial variations observed in liquid-phase epitaxial garnet films of nominal composition Er2Eu1Ga0.7Fe4.3O12. Data are given for a film whose thickness was constant to ± 2.5% over an area of 0.6 cm2.

Bibliography of Digital Magnetic Circuits and Materials

A list of about 400 references relating to magnetic memory and logic circuits has been made. The bibliography is divided into 19 sections. Several sections are devoted to the physical, magnetic, and switching parameters of magnetic materials. Other parts cover the circuit and logical aspects of using magnetic cores, plates, ``twistors,'' thin films, and transfluxors. Attention is given to the use of special memory techniques such as domain wall viscosity readout, cross-field effects, and circuits operated with RF carriers, The use of magnetic cores as half adders, gates, and shift registers is recognized in a separate section. A listing of sources of further information (conference proceedings, books, and other bibliographies) is included.