Cosmic ray acceleration by stellar wind. Simulation for heliosphere

The solar wind deceleration by the interstellar medium may result in the existence of the solar wind terminal shock. In this case a certain fraction of thermal particles after being heated at the shock would obtain enough energy to be injected to the regular acceleration process. An analytical solution for the spectrum in the frame of a simplified model that includes particle acceleration at the shock front and adiabatic cooling inside the stellar wind cavity has been derived. It is shown that the acceleration of the solar wind particles at the solar wind terminal shock is capable of providing the total flux, spectrum and radial gradients of the low-energy protons close to one observed in the interplanetary space

Synthesis, Structure, and Magnetic Properties of an Al2O3/Ge-p/Al2O3/Co Thin-Film System

Abstract—Structural and magnetic measurements are made of an Al2O3/Ge-p/Al2O3/Co thin-film system. The structure is synthesized via ion-plasma deposition and can be used as a tunnel heterostructure. The dependences of the magnetic properties of cobalt on the rate of its deposition and the rates of deposition of preceding layers are established

The role of the semiconductor layer in the exchange-bias film structure of CoNi / Si / FeNi / Si with a spin spring effect

CoNi / Si / FeNi / Si structures were synthesized by ion-plasma sputtering. A negative hysteresis loop bias was detected at the thickness of the silicon layer was less than 2 nm and the temperature was less than 100 K. A positive hysteresis loop bias was detected at the thickness of the silicon layer was more than 2 nm and the temperature greater than 100K

Effect of the Semiconductor Spacer on Positive Exchange Bias in the CoNi/Si/FeNi Three-Layer Structure

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Films consisting of a hard magnetic ferromagnet CoNi and a soft magnetic ferromagnet FeNi interacting through a nonmagnetic Si semiconductor spacer are experimentally studied. The temperature and field dependences of the magnetic properties of film structures with different silicon thicknesses are examined. It is found that the multilayer structure has the properties inherent in magnetic springs and exhibits positive exchange bias as a function of the silicon thicknes

The Study of Co-Cu Heterogeneous Alloy Thin Films by NMR Method

В данной работе обсуждаются результаты, полученные при исследовании структуры магнитных слоев в мультислойных пленках Co/Cu со сверхтонкими магнитными слоями, приготовленных методом магнетронного ионно-плазменного распыления, методом ЯМР на ядрах 59Co (эффективная толщина слоя Co составляла dCo ≈ 3.5 и 4.5A). Несмотря на столь малые зна- чения эффективной толщины слоев, было обнаружено, что спектры ЯМР представляли собой суперпозицию двух пиков с центральными частотами f1=190−196МГц и f2=208−213МГц, которые, очевидно, соответствовали атомам кобальта, имеющим 0 и 1 атом меди в ближай- шем окружении. Данный факт указывает на то, что кобальт главным образом организуется в крупные кластеры, включающие большое число атомов.In the present work we discuss the structure of magnetic layer in magnetron sputtered Co/Cu multilayers with ultrathin magnetic layers ( effective layer thicknesses dCo ≈ 3.5 and 4.5A) obtained by means of 59Co NMR method. In spite of such a small effective thicknesses of sputtered layers it has been found that the NMR spectra are the superposition of two peaks with central frequencies f1=190-196MHz and f2=208- 213MHz which obviously correspond to Co-atoms which have 0 and 1 Cu-atom in the nearest-neighbor shell indicating that cobalt preferably forms clusters with large number of atoms involved

Solid-state Synthesis of Cobalt Germanides in Epitaxial Ge/α-Co(001) and Ge/β-Co(110) Nanofilms

Представлены экспериментальные результаты исследования твёрдофазного синтеза германидов кобальта в эпитаксиальных Ge/α-Co(001) и Ge/β-Co(110) нанопленках. Показано, что для обеих полиморфных модификаций кобальта фаза Co5Ge7 формируется первой при температуре ~275◦C. С увеличением температуры отжига при температуре ~300◦C образуется фаза CoGe2, которая резко уменьшает электрическое сопротивление и намагниченность образцов. Различные полиморфные модификации кобальта не изменяют последовательность формирования фаз и их температур инициирования.The experimental results of a study of solid-state synthesis of cobalt germanides in epitaxial Ge/α-Co(001) and Ge/β-Co(110) nanofilms are presented. For both polymorphic modifications of cobalt, it is demonstrated that the Co5Ge7 phase occurs at ~275◦C. When the annealing temperature increases to ~300◦C, the CoGe2 phase forms, which sharply reduces the electric resistance and magnetic characteristics of the samples. The order of the formation of phases and the temperatures at which the phases are formed are not changed based on the polymorphic modification of cobalt