An electron holography study of perpendicular magnetic tunnel junctions nanostructured by deposition on pre-patterned conducting pillars

Electron holography investigation of the magnetic induction field of perpendicular magnetic tunnel junctions for the fabrication of magnetic random access memories (MRAM), and temperature behavior.

Quaternionic representation of electromagnetism for material media

In this study, the electromagnetic fields are developed in the presence of both the electric and magnetic induction fields by quaternion algebra. In this sense, the polarization and magnetization effects, which are valid in the material media, gain much importance. Quaternions are one of the most convenient tools for representing electromagnetism with regard to having non-commutative but associative algebraic division ring. By defining the quaternion induction field, the quaternion source term has been obtained in basic and elegant notation for the first time. In addition, one type of Poynting theorem, named as the Minkowski form, has been presented including the permittivity and permeability constants by quaternions.

Penentuan Permeabilitas Magnet Melalui Percobaan Induksi Magnet dengan Logger Lite

In magnet world learning, the discussion of the µ magnetic permeability concept has not yet been addressed specifically. The magnetic permeability often discussed is the µ0 vacuum permeability whose value is 4p x 10-7 Tm/A. In fact, the permeability value of objects is not the same as the vacuum permeability. Therefore, it is necessary to conduct experiments on this in order to obtain an adequate understanding of its concepts. The experimental devices include Logger Lite devices, solenoids, computer, power supply, and two types of ferromagnetic materials i.e. steel and white metal which are precisely similar in both lengths. The deciding of the material permeability is done by placing the materials on the solenoid varying electric current (i) which flows in the solenoid and records the induction field produced (B). Then, based on the data set of I towards B, it’s done a linear regression. The material permeability is determined from the slope of the graph.Based on the experiment, the permeability value of vacuum results mo = (4p ± 0,34) x 10-7 Tm/A. Whereas, for each experimented material it shows that the steel is is m = (8.24 ± 0,008) x 10-6 Tm/A and the white metal is m = (1.85 ± 0,002) x 10-5 Tm/A. Based on the experiment, it’s obvious that the permeability concept seems more and more tangible.