Fabrication of spherical particles with mixed amorphous / crystalline nanostructured cores and insulating oxide shells
By spark-eroding Fe75Si15B10 in water/ethanol mixtures, spherical particles with nanostructured cores consisting of mixed amorphous and crystalline phases were produced. The relative volume fractions of the amorphous and crystalline phases were dependent on the water/ethanol ratio. In the same process, continuous oxide layers were formed on the particle surfaces. The basic mechanisms responsible for the formation of the surface oxide layers and the core nanostructures were modeled. At frequencies ranging from 1 to 100 MHz, the combination of the core nanostructures and the insulating oxide shells yielded exceptionally low-loss magnetic behavior.
Nano‐Scale Materials Development for Future Magnetic Applications
Developments in the field of magnetic materials which show promise for future applications are reviewed. In particular recent work in nanocrystalline materials is reviewed, with either soft or hard behavior as well as advances in the magnetic materials used for magnetic recording. The role of microstructure on the extrinsic magnetic properties of the materials is stressed and it is emphasized how careful control of the microstructure has played an important role in their improvement. Important microstructural features such as grain size, grain shape and crystallographic texture all are major contributors to the properties of the materials. In addition, the critical role that new instrumentation has played in the better understanding of the nano-phase magnetic materials is demonstrated.
La inseguridad jurídica en normas de contratación estatal
It is established by different studies that the issue of government procurement has been marred by several factors, the test objective to publicize these factors, we take as starting point the constant conflict between the branches of government to try and organize this subject; will collect and analyze diverse regulatory and case material in order to achieve evidence and demonstrate the different concepts of constant change that produces excessive regulation of the subject procurement and is in turn causing rapid changes that result in legal uncertainty for our law on the Contract Status.