Current-perpendicular-to-plane giant magnetoresistance of a spin valve using Co2MnSi Heusler alloy electrodes

We report the current-perpendicular-to-plane giant magnetoresistance of a spin valve with Co2MnSi (CMS) Heusler alloy ferromagnetic electrodes. A multilayer stack of Cr/Ag/Cr/CMS/Cu/CMS/Fe25Co75/Ir28Mn72/Ru was deposited on a MgO (001) single crystal substrate. The bottom CMS layer was epitaxially grown on the Cr/Ag/Cr buffer layers and was ordered to the L21 structure after annealing at 673 K. The upper CMS layer was found to grow epitaxially on the Cu spacer layer despite the large lattice mismatch between Cu and CMS. The highest MR ratios of 8.6% and 30.7% for CPP-GMR were recorded at room temperature and 6 K, respectively. The high spin polarization of the epitaxial CMS layers is the most likely origin of the high MR ratio.Comment: 14 pages, 3 figures, presented at the 53rd Annual Conference on Magnetism and Magnetic Materials, to be published in J. Appl. Phy

A scheduling and diagnostic system for scientific satellite GEOTAIL using expert system

The Intelligent Satellite Control Software (ISACS) for the geoMagnetic tail observation satellite named GEOTAIL (launched in July 1992) has been successfully developed. ISACS has made it possible by applying Artificial Intelligence (AI) technology including an expert system to autonomously generate a tracking schedule, which originally used to be conducted manually. Using ISACS, a satellite operator can generate a maximum four day period of stored command stream autonomously and can easily confirm its safety. The ISACS system has another function -- to diagnose satellite troubles and to suggest necessary remedies. The workload of satellite operators has drastically been reduced since ISACS has been introduced into the operations of GEOTAIL

LOW-PRESSURE MICRO PLASMA GENERATION USING MICROWAVE IN A MIRROR MAGNETIC FIELD

Microsize plasma sources have not been developed for the condition of low-pressure range less than 0.1Torr in the present technology. In this article we investigate a 2.45GHz microwave discharge operated at the ECR and the 2^ harmonic ECR, by mirror magnetic field.Nagasaki Symposium on Nano-Dynamics 2008 (NSND2008) 平成20年1月29日(火)於長崎大学 Poster Presentatio

Anotação Genômica de Bradyrhizobium japonicum estirpes CPAC 15 e CPAC 7: Resultados parciais e sua importância para a cultura de soja.

O solo é um importante complexo onde encontram-se nutrientes essenciais para as plantas. A maioria das plantas necessita de grandes quantidades de nitrogênio, todavia, este em geral se encontra de forma pouco assimilável no solo. Contudo, existem bactérias que são capazes de fixar o nitrogênio atmosférico (N2), disponibilizando-o para as plantas através de uma relação simbiõtica. Dentre estes, destaca-se a espécie Bradyrhizobium japonicum, com as estirpes CPAC 15 (=SEMIA 5079) e CPAC 7 (=SEMIA 5080), as quais são amplamente utilizadas como inoculantes para a cultura da soja (Glycine max (L.) Merr.) no Brasil. O presente trabalho teve como objetivo realizar a anotação manual do genoma de ambas as estirpes. Para isso, as sequências obtidas foram submetidas à anotação e à montagem utilizando o software ?System for Automated Bacterial Integrated Annotation? (SABIA), que integra vários programas de domínio público. Foram definidas as coding sequences (CDSs), que foram classificadas como hipotéticas, hipotéticas conservadas, válidas e não válidas. Os resultados mostraram elevada similaridade entre ambas as estirpes, com pequena diferença na quantidade de CDSs relacionadas ao transporte transmembrana e replicação em reparo, as quais estavam em maior quantidade na estirpe CPAC 15, provavelmente devido ao seu destaque como maior competitividade. Cerca de 50% do genoma apresentou CDSs classificadas como hipotéticas, sendo então necessários mais estudos para determinar a função desses genes.Fertbio

Significant effect of interfacial spin moments in ferromagnet-semiconductor heterojunctions on spin transport in a semiconductor

Using controlled ferromagnet (FM) -semiconductor (SC) interfaces in SC-based lateral spin-valve (LSV) devices, we experimentally study the effect of interfacial spin moments in FM-SC heterojunctions on spin transport in SC. First-principles calculations predict that the spin moment of FM-SC junctions can be artificially reduced by inserting 3d transition metal V, Cr, or Cu atomic layers between FM and SC. When all-epitaxial FM-SC Schottky-tunnel contacts with a 0.4-0.5-nm-thick V, Cr, or Cu interfacial layer are formed, we find that the spin signals in FM-SC LSV devices are significantly decreased at 8 K. When we increase the interfacial spin moment by inserting an ∼0.3-nm-thick Co layer between FM and SC, the spin signals at 8 K are significantly enhanced again. From these experiments, we conclude that the interfacial spin moments at FM-SC interfaces are one of the important factors to achieve large spin signals even in SC-based spintronic devices.T. Naito, R. Nishimura, M. Yamada, A. Masago, Y. Shiratsuchi, Y. Wagatsuma, K. Sawano, R. Nakatani, T. Oguchi, and K. Hamaya, Significant effect of interfacial spin moments in ferromagnet-semiconductor heterojunctions on spin transport in a semiconductor, Phys. Rev. B 105, 195308