Temperature gradient-induced magnetization reversal of single ferromagnetic nanowires

In this study, we investigate the temperature- and temperature gradient-dependent magnetization reversal process of individual, single-domain Co39Ni61 and Fe15Ni85 ferromagnetic nanowires via the magneto-optical Kerr effect and magnetoresistance measurements. While the coercive fields (HC) and therefore the magnetic switching fields (HSW) generally decrease under isothermal conditions at elevated base temperatures (Tbase), temperature gradients (ΔT) along the nanowires lead to an increased switching field of up to 15% for ΔT  = 300 K in Co39Ni61 nanowires. This enhancement is attributed to a stress-induced, magneto-elastic anisotropy term due to an applied temperature gradient along the nanowire that counteracts the thermally assisted magnetization reversal process. Our results demonstrate that a careful distinction between locally elevated temperatures and temperature gradients has to be made in future heat-assisted magnetic recording devices

Itinerant and localized magnetic moments in ferrimagnetic Mn(2)CoGa thin films probed by x-ray magnetic linear dichroism: Experiment and ab initio theory

Meinert M, Schmalhorst J-M, Klewe C, et al. Itinerant and localized magnetic moments in ferrimagnetic Mn(2)CoGa thin films probed by x-ray magnetic linear dichroism: Experiment and ab initio theory. Physical Review B. 2011;84(13): 132405.Epitaxial thin films of the half-metallic Xa compound Mn(2)CoGa (Hg(2)CuTi prototype) were prepared by dc magnetron co-sputtering with different heat treatments on MgO (001) substrates. High-quality films with a bulk magnetization of 1.95(5) mu(B) per unit cell were obtained. The L(3,2) x-ray magnetic circular dichroism spectra agree with calculations based on density functional theory (DFT) and reveal the antiparallel alignment of the two inequivalent Mn moments. X-ray magnetic linear dichroism, in good agreement with theory as well, allows us to distinguish between itinerant and local Mn moments. Based on noncollinear spin DFT, it is shown that one of the two Mn moments has local character, whereas the other Mn moment and the Co moment are itinerant

Origin and diversification of Cristaria (Malvaceae) parallel Andean orogeny and onset of hyperaridity in the Atacama Desert

The Atacama Desert in western South America is considered as one of the driest places on earth, but is nevertheless characterized by surprisingly high species richness and levels of endemism. The plant genus Cristaria (Malvaceae), with ca. 21 species, is one of the most diverse genera of the Atacama Desert, while the much less diverse sister genus Lecanophora (7 species) is found east of the Andes. Here, we use DNA sequence data and divergence time estimates in order to investigate the biogeographical history of the Atacama species of Cristaria. We further investigate a possible influence of Andean uplift and the subsequent onset of hyperaridity in the Atacama Desert on diversification times in Cristaria. We sequenced three plastid markers (ndhF, trnK(matK) & rpl16) for 19 species of Cristaria and two species of Lecanophora from the Atacama Desert and Argentina, respectively. Further, we included sequences of the same plastid regions from GenBank in order to get a comprehensive dataset of Malvoideae. Phylogenetic relationships were inferred using maximum likelihood and Bayesian analyses, and divergence times were estimated with BEAST2. Our results place the monophyletic genera Cristaria and Lecanophora as sister groups in a Glade sister to the rest of Malveae. The split between these two lineages (similar to 20 Ma) correlates with Andean uplift during the early Miocene, indicating a vicariant event. During the late Miocene, two Mediterranean members of Cristaria separated from the major Atacama Glade. The subsequent diversification of the latter one correlates with the onset and subsequent temporal expansion of hyperarid conditions in the Atacama Desert since the late Miocene and during the Quaternary climate oscillations

Transforming knowledge systems for life on Earth : Visions of future systems and how to get there

Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent.Peer reviewe

Transforming knowledge systems for life on Earth: Visions of future systems and how to get there

Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent

Transforming knowledge systems for life on Earth: Visions of future systems and how to get there

Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent

Make EU trade with Brazil sustainable

Brazil, home to one of the planet's last great forests, is currently in trade negotiations with its second largest trading partner, the European Union (EU). We urge the EU to seize this critical opportunity to ensure that Brazil protects human rights and the environment