Preparation of Fe-Pt thin-sheet magnets using exfoliation behavior

In this research, Fe-Pt thin sheets thicker than 10 microns with Fe contents ranging from 50 to 60 at.% were prepared. Isotropic Fe-Pt thin sheets could be obtained by taking advantage of the exfoliation behavior after depositing Fe-Pt films on Si substrates using a laser ablation technique. A post-annealing process was used to obtain the L10 phase, and the (BH)max value of Fe-Pt thin sheets showed approximately 70 kJ/m3. Moreover, the test of a cantilever containing the obtained Fe-Pt thin sheet showed good mechanical characteristics

Nd-Fe-B film magnets with the thickness above 100 μm deposited on Si substrates

Although increase in thickness of an Nd-Fe-B film magnet is indispensable to provide a sufficient magnetic field, it was difficult to suppress the peeling phenomenon due to the different values of a linear expansion coefficient for a Si substrate and a Nd-Fe-B film even if a buffer layer such as a Ta film was used. In this report, it was confirmed that a control of the microstructure for PLD (Pulsed Laser Deposition)-fabricated Nd-Fe-B films enabled us to increase the thickness up to approximately 160 μm without a buffer layer on a Si substrate. Namely, we found that the precipitation of Nd element at the boundary of Nd-Fe-B grains together with the triple junctions due to the composition adjustment is effective to suppress the destruction of the samples through an annealing process. The magnetic properties of the prepared films were comparable to those of previously reported ones deposited on metal substrates. Although the mechanism is under investigation, the above-mentioned film had stronger adhesive force compared with that of a sputtering-made film. Resultantly, no deterioration of mechanical together with magnetic properties could be observed after a dicing process.2015 IEEE International Magnetics Conference, INTERMAG 2015; Beijing; China; 11 May 2015 through 15 May 201

Improvement of the magnetic properties of Nd–Fe–B/glass two-layer films deposited on Si substrates

In a previous study, the authors developed Nd–Fe–B/glass two-layer films deposited on Si substrates using pulsed laser deposition for micro electro mechanical systems. Here, the fabrication conditions of the films were investigated to determine the optimum conditions that enhance the magnetic properties of the films. The annealing time in the pulse-annealing process conducted after the deposition was set to 4.0 s at Nd contents of 14 at.–16 at.%. Moreover, the effect of the glass/Nd–Fe–B thickness ratio on the magnetic properties was examined. A ratio less than 2 resulted in an increase in (BH)max up to 80 kJ/m3

Spintronics: Fundamentals and applications

Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio

Identification of an OsPR10a promoter region responsive to salicylic acid

Orysa sativa pathogenesis-related protein 10a (OsPR10a) was induced by pathogens, salicylic acid (SA), jasmonic acid (JA), ethephon, abscisic acid (ABA), and NaCl. We tried to analyze the OsPR10a promoter to investigate the transcriptional regulation of OsPR10a by SA. We demonstrated the inducibility of OsPR10a promoter by SA using transgenic Arabidopsis carrying OsPR10a:GFP as well as by transient expression assays in rice. To further identify the promoter region responsible for its induction by SA, four different deletions of the OsPR10a promoter were made, and their activities were measured by transient assays. The construct containing 687-bp OsPR10a promoter from its start codon exhibited a six-fold increase of induction compared to the control in response to SA. Mutation in the W-box like element 1 (WLE 1) between 687 and 637-bp from TGACA to TGAAA completely abolished induction of the OsPR10a promoter by SA, indicating that the WLE 1 between −687 and −637 of OsPR10a promoter is important in SA-mediated OsPR10a expression. We show for the first time that the W-box like element plays a role in SA mediated PR gene expression

An Intergenic Region Shared by At4g35985 and At4g35987 in Arabidopsis Thaliana is a Tissue Specific and Stress Inducible Bidirectional Promoter Analyzed in Transgenic Arabidopsis and Tobacco Plants

On chromosome 4 in the Arabidopsis genome, two neighboring genes (calmodulin methyl transferase At4g35987 and senescence associated gene At4g35985) are located in a head-to-head divergent orientation sharing a putative bidirectional promoter. This 1258 bp intergenic region contains a number of environmental stress responsive and tissue specific cis-regulatory elements. Transcript analysis of At4g35985 and At4g35987 genes by quantitative real time PCR showed tissue specific and stress inducible expression profiles. We tested the bidirectional promoter-function of the intergenic region shared by the divergent genes At4g35985 and At4g35987 using two reporter genes (GFP and GUS) in both orientations in transient tobacco protoplast and Agro-infiltration assays, as well as in stably transformed transgenic Arabidopsis and tobacco plants. In transient assays with GFP and GUS reporter genes the At4g35985 promoter (P85) showed stronger expression (about 3.5 fold) compared to the At4g35987 promoter (P87). The tissue specific as well as stress responsive functional nature of the bidirectional promoter was evaluated in independent transgenic Arabidopsis and tobacco lines. Expression of P85 activity was detected in the midrib of leaves, leaf trichomes, apical meristemic regions, throughout the root, lateral roots and flowers. The expression of P87 was observed in leaf-tip, hydathodes, apical meristem, root tips, emerging lateral root tips, root stele region and in floral tissues. The bidirectional promoter in both orientations shows differential up-regulation (2.5 to 3 fold) under salt stress. Use of such regulatory elements of bidirectional promoters showing spatial and stress inducible promoter-functions in heterologous system might be an important tool for plant biotechnology and gene stacking applications

Ethylene-inducible DNA binding proteins that interact with an ethylene-responsive element.

We demonstrated that the GCC box, which is an 11-bp sequence (TAAGAGCCGCC) conserved in the 5' upstream region of ethylene-inducible pathogenesis-related protein genes in Nicotiana spp and in some other plants, is the sequence that is essential for ethylene responsiveness when incorporated into a heterologous promoter. Competitive gel retardation assays showed DNA binding activities to be specific to the GCC box sequence in tobacco nuclear extracts. Four different cDNAs encoding DNA binding proteins specific for the GCC box sequence were isolated, and their products were designated ethylene-responsive element binding proteins (EREBPs). The deduced amino acid sequences of EREBPs exhibited no homology with those of known DNA binding proteins or transcription factors; neither did the deduced proteins contain a basic leucine zipper or zinc finger motif. The DNA binding domain was identified within a region of 59 amino acid residues that was common to all four deduced EREBPs. Regions highly homologous to the DNA binding domain of EREBPs were found in proteins deduced from the cDNAs of various plants, suggesting that this domain is evolutionarily conserved in plants. RNA gel blot analysis revealed that accumulation of mRNAs for EREBPs was induced by ethylene, but individual EREBPs exhibited different patterns of expression