Magnetic properties, anisotropy, and microstructure of sputtered rare-earth iron multilayers

A study of compositionally modulated magnetic films of the form Fe/RE, particularly for RE=Nd and Dy, has been performed by vibrating sample magnetometry, ac susceptibility and x-ray diffraction. The relationship between the magnetic properties and the layer thickness was studied systematically for X-Å Fe/Y-Å Dy, as the layer thicknesses X and Y were varied from 1.8 to 20 Å. The ranges of layer thicknesses required for perpendicular anisotropy were determined. The interface and volume anisotropy energies were estimated for X-Å Fe/Y-Å Nd and the differences in the magnetic properties between X-Å Fe/7-Å Dy and X-Å Fe/7-Å Nd are discussed. Journal of Applied Physics is copyrighted by The American Institute of Physics

Introgression and pyramiding into common bean market class fabada of genes conferring resistance to anthracnose and potyvirus

Anthracnose and bean common mosaic (BCM) are considered major diseases in common bean crop causing severe yield losses worldwide. This work describes the introgression and pyramiding of genes conferring genetic resistance to BCM and anthracnose local races into line A25, a bean genotype classified as market class fabada. Resistant plants were selected using resistance tests or combining resistance tests and marker-assisted selection. Lines A252, A321, A493, Sanilac BC6-Are, and BRB130 were used as resistance sources. Resistance genes to anthracnose (Co-2 ( C ), Co-2 ( A252 ) and Co-3/9) and/or BCM (I and bc-3) were introgressed in line A25 through six parallel backcrossing programs, and six breeding lines showing a fabada seed phenotype were obtained after six backcross generations: line A1258 from A252; A1231 from A321; A1220 from A493; A1183 and A1878 from Sanilac BC6-Are; and line A2418 from BRB130. Pyramiding of different genes were developed using the pedigree method from a single cross between lines obtained in the introgression step: line A1699 (derived from cross A1258 × A1220), A2438 (A1220 × A1183), A2806 (A1878 × A2418), and A3308 (A1699 × A2806). A characterization based on eight morpho-agronomic traits revealed a limited differentiation among the obtained breeding lines and the recurrent line A25. However, using a set of seven molecular markers linked to the loci used in the breeding programs it was possible to differentiate the 11 fabada lines. Considering the genetic control of the resistance in resistant donor lines, the observed segregations in the last backcrossing generation, the reaction against the pathogens, and the expression of the molecular markers it was also possible to infer the genotype conferring resistance in the ten fabada breeding lines obtained. As a result of these breeding programs, genetic resistance to three anthracnose races controlled by genes included in clusters Co-2 and Co-3/9, and genetic resistance to BCM controlled by genotype I + bc-3 was combined in the fabada line A3308

Thermal and structural stability of cosputtered amorphous Ta\u3csub\u3ex\u3c/sub\u3eCu\u3csub\u3e1-x\u3c/sub\u3e alloy thin films on GaAs

The thermal and chemical stabilities of amorphous-metal diffusion barrier films are of importance in high-temperature semiconductor device applications. The reaction characteristics of the barrier constituents with the surrounding elements as well as the crystallization temperature determine the thermal stability of an amorphous-alloy diffusion barrier. We report that suitable thin films of Ta-Cu have been prepared over a wide range of compositions, by cosputter deposition onto GaAs and fused-quartz substrates. The amorphous nature and crystallization behavior of the films have been monitored by x-ray diffraction and van der Pauw resistivity measurements. Films were found to be amorphous over the range of 55–95 at. % Ta. In addition, Auger electron spectroscopy surveys and depth profiles were used to investigate the various interdiffusion reactions between the amorphous diffusion barrier, polycrystalline Au overlayers, and GaAs substrates. Barriers of Ta93Cu7 are remarkably effective in preventing Au in-diffusion, a 3000-Å layer remaining unpenetrated after an annealing at 700 °C for 20 min. Diffusion of Ga and/or As into amorphous 93 at. % Ta is more rapid than that of Au. Interfacial reactions formed Ta3Au, CuAu, TaAs2, Ga3Cu7, Cu3As, and other unidentified compounds formed above 700 °C. Journal of Applied Physics is copyrighted by The American Institute of Physics

Highly oriented Tl\u3csub\u3e2\u3c/sub\u3eBa\u3csub\u3e2\u3c/sub\u3eCa\u3csub\u3e2\u3c/sub\u3eCu\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e10\u3c/sub\u3e thin films by pulsed laser evaporation

We have fabricated superconducting thin films on MgO(100) substrates with nearly pure Tl2Ba2Ca2Cu3O10 (2:2:2:3) phase using pulsed laser evaporation and post-annealing. The films had c axes perpendicular to the substrates. Superconducting films with onset temperatures of 125 K and zero resistance at 110 K were obtained. X-ray microprobe fluorescence measurements indicate that a typical composition of films is Tl0.66Ba1.77Ca1.46Cu3Oχ, which is low in Tl compared to that expected for the 2:2:2:3 phase. A typical grain size is greater than 10 µm as revealed by scanning electron microscopy

Benchmarking Minnesota’s Environmental Review and Permitting Processes for Forestry and Mining Industries: A Comparative Assessment

This report was prepared in response to 2005 Minnesota Session Laws, Chapter 1, Section 2, Subsection 7, requiring the commissioner of the Minnesota Pollution Control Agency to submit a report to the Minnesota House and Senate Environment and Natural Resources Policy and Finance Committees benchmarking Environmental Review and permitting laws and procedures in Minnesota with states containing comparable forestry and mining development projects. The report consists of a review of state environmental review programs, case studies of four forestry and four mining development projects, and results of a focus group meeting with state environmental review and permitting project managers