5,776 research outputs found
Pulsed Laser Deposition of Rocksalt Magnetic Binary Oxides
Here we systematically explore the use of pulsed laser deposition technique
(PLD) to grow three basic oxides that have rocksalt structure but different
chemical stability in the ambient atmosphere: NiO (stable), MnO (metastable)
and EuO (unstable). By tuning laser fluence, an epitaxial single-phase nickel
oxide thin-film growth can be achieved in a wide range of temperatures from 10
to 750 {\deg}C. At the lowest growth temperature, the out-of-plane strain
raises to 1.5%, which is five times bigger than that in a NiO film grown at 750
{\deg}C. MnO thin films that had long-range ordered were successfully deposited
on the MgO substrates after appropriate tuning of deposition parameters. The
growth of MnO phase was strongly influenced by substrate temperature and laser
fluence. EuO films with satisfactory quality were deposited by PLD after oxygen
availability had been minimized. Synthesis of EuO thin films at rather low
growth temperature prevented thermally-driven lattice relaxation and allowed
growth of strained films. Overall, PLD was a quick and reliable method to grow
binary oxides with rocksalt structure in high quality that can satisfy
requirements for applications and for basic research
Responses of Agroecosystems to Climate Change: Specifics of Resilience in the Mid-Latitude Region
This study examines the productivity and resilience of agroecosystems in the Korean Peninsula. Having learned valuable lessons from a Chapman University project funded by the United States Department of Agriculture which concentrated on the semi-arid region of southwestern United States, our joint Korea—Chapman University team has applied similar methodologies to the Korean Peninsula, which is itself an interesting study case in the mid-latitude region. In particular, the Korean Peninsula has unique agricultural environments due to differences in political and socioeconomic systems between South Korea and North Korea. Specifically, North Korea has been suffering from food shortages due to natural disasters, land degradation and political failure. The neighboring developed country, South Korea, has a better agricultural system but a low food self-sufficiency rate. Therefore, assessing crop yield potential (Yp) in the two distinct regions will reveal vulnerability and risks of agroecosystems in the mid-latitude region under climate change and variability and for different conditions
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