Showing 2 results for Ferromagnetic
Vahid Ahadnejad,
Volume 13, Issue 4 (2-2014)
Abstract
The magnetic anisotropy of rocks results from the contributions of diamagnetic, paramagnetic, & ferromagnetic minerals. This bulk anisotropy of magnetic susceptibility, which can be rapidly measured with modern instruments, generally provides a better understanding of the rock deformation history. Different minerals in a rock can form at different times and also respond to deformation in different manners. Therefore it is useful to separate their respective contributions to the whole rock magnetic fabric. Various techniques available to achieve this separation among them measurement of the magnetic properties at high fields, above the saturation magnetization of ferromagnetic minerals, effectively separates the diamagnetic-paramagnetic magnetic anisotropy. In this paper, the anisotropies of ferromagnetic and paramagnetic components are separated using High-Field Analysis torque for 37 samples of natural rocks. These samples are igneous rocks of Malayer that are mainly composed of paramagnetic minerals (e.g. biotite and amphibole) and few portions of ferromagnetic minerals (e.g. titanomagnetite) which are located in the quratz-feldespathic (diamagnetic) context. Anisotropy of Magnetic Susceptibility (AMS) in low field analyses indicated that paramagnetic phases are the dominant control of the magnetic fabric. This is confirmed by High Field Analyses (HFA) which implied that magnetic characteristics are dominated by paramagnetic minerals, except for three samples.
Zhaleh Ebrahimi, Ali Asghar Shokri,
Volume 14, Issue 1 (4-2014)
Abstract
in this paper, the effect of rough interface is investigated on spin dependent transmission in a magnetic tunneling junction. For calculating of transmission probability the transfer matrix technique and the approximation of effective mass is used in calculations. The mentioned magnetic structure includes of two semiconductor ferromagnetic separated by a nonmagnetic layer which is attached to two metal nonmagnetic electrodes. The different components of spin dependent transmission probability (direct and indirect) in the presence of roughness is studied while the roughness is distributed as random islands in interfaces. The results of calculations show that roughness affects the transport of incident electrons through mentioned double barrier structure, effectively. Because the scattering due to roughness of interface and therefore opening addition conduction channels, results to reduce the peak of incident electrons transmission probability. Also, the effect of percent of interface roughness is studied on component of indirect transmission probability.
