Coercivity is an important concept for proving existence and uniqueness of solutions to variational problems in Hilbert spaces. But, while the existence of coercivity estimates is well known for many variational problems arising from partial differential equations, it is still an open problem in the context of boundary integral operators arising from acoustic scattering problems, where rigorous...

cofe/cu multilayer nanowires were electrodeposited into anodic aluminum oxide templates prepared by a two-step mild anodization method, using the single-bath technique. nanowires with 30 nm diameter and the definite lengths were obtained. the effect of cofe layers thickness and annealing on the magnetic behavior of the multilayer nanowires was investigated. the layers thickness was controlled t...

A special instrument has been built to measure the coercivity directly on steel sheets without having to cut samples. It will be used to perform the 8000 coercivity measurements which will be needed during the production of the ll'OOO ton of steel sheets for the LEP dipole magnets. The coercimeter allows local and directional coercivity measurements to be made on a steel sheet with an accuracy ...

The temperature dependence of the magnetic properties of titanium modified cobalt ferrite is presented. The change of maximum magnetization obtained at H ≈ 2.4 MA/m between any two temperatures increases systematically with composition, which is desirable for applications in devices. Variation in magnetocrystalline anisotropy and coercivity were different from previous studies on cation substit...

Perpendicular magnetization and precise control over the magnetic easy axis in magnetic thin film is necessary for a variety of applications, particularly in magnetic recording media. A strong (111) orientation is successfully achieved in the CoFe2O4 (CFO) thin film at relatively low substrate temperature of 100 °C, whereas the (311)-preferred randomly oriented CFO is prepared at room temperatu...

Sputtering pressure effects and temperature-dependent magnetism of Co/Pd multilayers" (1994). David Sellmyer Publications. Paper 102. The temperature dependence of the sputtering Ar pressure effects on magnetic properties and the coercivity mechanism of Co(2 &/Pd(13 A) multilayers were studied as the sputtering Ar pressure varied from 3-15 mTorr and the temperature from 300 to 35 K. It is found...

We present an experimental model system that enables quantitative assessment of intergranular exchange coupling in CoCrPt-oxide perpendicular magnetic recording media. A thin film structure consisting of a high coercivity CoPt unicrystal layer and a lower coercivity CoPt layer separated by a thin oxide interlayer is used to model perpendicularly magnetized grains separated by oxide grain bounda...

Many interesting properties of polynomials are closely related to the geometry of their Newton polytopes. We analyze the coercivity on R of multivariate polynomials f ∈ R[x] in terms of their Newton polytopes. In fact, we introduce the broad class of so-called gem regular polynomials and characterize their coercivity via conditions imposed on the vertex set of their Newton polytopes. These cond...

It was observed that the coercivity of CoCrPt films deposited on a polyimide tape was much lower than the coercivity deposited on a rigid glass substrate under identical conditions. X-ray diffraction showed that the desirable ~112! and ~110! texture of the NiAl/CrMn underlayers on the tape substrate was severely degraded during the deposition process. This resulted in the destruction of ~10.0! ...

Local coercivity variation of Co/Pd nanomultilayers has been investigated by measuring the polar Kerr hysteresis loops of the local areas of submicron size using a magneto-optic Kerr microscope system. Interestingly, the local coercivity distribution was very sensitive to an increase in the number of repeats: the ~2 Å Co/11 Å Pd)10 sample showed a smooth variation of the local coercivity, while...