The "SOil Functional biodiversity as an Indicator of Agroecosystems management" (SOFIA) project aims at shading more light on environmental issues related to cropped agroecosystems management, climate change and biodiversity conservation. It specifically addresses the impact of agricultural practices on the taxonomic and functional diversity of living communities in the soil, and the effects of those practices on some of the functions the soil sustains: regulation (greenhouse gases emissions, carbon storage), supply (availability of nutrients for crop production) and maintenance of biodiversity (soil fauna and flora). This project brings together eight academic (universities, INRA) and one private (Agrotransfert) partners. It builds a part of its experimental design on the Estrées-Mons site (22 ha, Somme, north of France) managed by INRA and setup in 2010. This site is dedicated to the study of long-term anthropogenic disturbance on biogeochemical cycles and biodiversity (ORE –ACBB) and focuses especially on disturbances brought by cropping. The site is characterized by a series of experimental treatments comprising varying levels of crop rotation (eg. annual, perennial and energy-based crop rotations), mineral inputs (nitrogen) and tillage practices. Hence, these treatments significantly modulate the amount, chemical nature and location of food resources for soil organisms but also their physical habitat. All along the project, the partners will monitor the induced-differentiation of the agroecosystems setup 2010 in terms of agronomic variables (plant biomass production) and soil physical and chemical variables. Concomitantly and by taking into account the significance of ecosystem services supported soil organisms, the project will characterize earthworms, macro-invertebrates, microfauna, bacterial and fungal communities taxonomic and functional diversity as well as its dynamic. Finally, some of the soil functions that are known to be greatly affected by these communities will be quantified: carbon and nitrogen mineralization, decomposition of plant residues, N2O emissions for instance. Laboratory experiments will also be performed and, both field and laboratory, results shall be used to test and improve biotic and abiotic indicators of soil functioning. In the end, the SOFIA project aims at the proposal of indicators that could better guide farmers choice, especially during transitions phases created by the evolution of cropping practices (introduction of energy crops, abandonment of tillage, reduced inputs, etc..). This project will also contribute to the improvement of indicators assessing the environmental impact of farming practices.

Giant Magnetoresistance (GMR) and Tunnel Magnetoresistance (TMR) are the two most important phenomena exploited in Spintronics, the field of electronics which exploits the electron spin. A specific constraint common to GMR and TMR devices is the need of two specific magnetic elements, of which magnetic moments can be made parallel or antiparallel in some controlled manner. The larger magnetoresistance generally found in TMR devices compared to GMR ones is due to the fact that tunneling depends critically on hybridization between states in the metal on one side and in the barrier on the other. One can think of a new device in which the resistance variation would result from the change in the tunnel resistance across a barrier resulting from the rotation of the moment in a magnetic element, under the effect of the Spin-Orbit Coupling (SOC). This is Tunnel Anisotropic Magnetoresistance (TAMR). TAMR requires one magnetic electrode only. This opens the way to exploring a number of new materials for spintronic devices. The first general objective of ETAM TAMR is to progress in the understanding of TAMR. One of the key questions to be answered is whether noncrystalline TAMR (depending on the direction of the moment with respect to the current, independent of the crystal structure) dominates crystalline TAMR (dependent on the orientation of the current and/or the moments within the crystal structure). A systematic experimental study in model FePt and CoPt films will be realized (temperature and angular dependence in particular). One will consider as well the dependence of TAMR on the nature of the insulating barrier. The experimental results will be compared to theoretical predictions based on first-principle tight-binding electronic structure calculations and using the two-channel version of Landauer-Bütttiker theory of transport. Model calculations will permit varying independently the microscopic parameters. The second general objective of ETAM TAMR is to find systems which show large TAMR effects at room temperature. Original routes will be explored : TAMR structures will be prepared which incorporate large-anisotropy rare-earth transition metal compounds (NdCo5) and structures will be prepared which incorporate high TN antiferromagnetic compounds (MnPt or MnPd3) (unlike GMR and TMR, TAMR does not require that the magnetic electrode be ferromagnetic). This project associates two French groups, P1 (CNRS-Néel) and P2 (INAC-CEA) and two Brazilian groups, P3 (IF-UFRJ Rio de Janeiro) and P4 (CDTN, Belo Horizonte). These various groups enjoy already fruitful collaboration and, importantly, they gather complementary expertise, as required to progress in this new scientific field : growth of L10 and L11 alloys (P2), of epitaxial Mn antiferromagnets (P4), of electrodeposited alloys (P3), growth of barriers (P1 and P2), X-ray synchrotron studies (P1 and P4), experimental analysis (magnetic and transport) (P1 and P3), model calculations (P1) and electronic structure calculations (P3). TAMR is a new possible effect which could be exploited in Spintronic devices. Any new development in a field of great prospect requires careful consideration, although it is certainly not possible at this stage to say how much it could impact the development of the field.