News Finding: "We were able to show that perfectly prepared materials actually have the properties that have been theoretically predicted."
Paper Finding: However, typically the highest spin polarizations of Heusler compounds obtained by this method amount to 60-70% at low temperatures 15 , with a single exception of 83-89% at 2 K, which collapses to C50% at room temperature 16 However, it is not clear, whether the predicted high magnetoresistance effects were not seen because the materials are contrary to predictions not half-metals or owing to the tunnel junction properties.
News Context: "It is not merely a breakthrough in the search for new spintronic materials but also in the interplay between theory and experiment," remarked Jourdan. "We were able to show that perfectly prepared materials actually have the properties that have been theoretically predicted." "Such a combination of electronic structure and theoretical photoemission calculations made direct comparison with the corresponding experimental data possible, which in turn was essential to interpreting the 100 percent spin polarization that was measured."
Paper Context: The magnetoresistance effect of planar tunnelling junctions between ferromagnetic electrodes is often related to the spin polarization by the application of the Jullière model 13 , which is justified only if the translational symmetry in the tunnelling process is completely broken. However, typically the highest spin polarizations of Heusler compounds obtained by this method amount to 60-70% at low temperatures 15 , with a single exception of 83-89% at 2 K, which collapses to C50% at room temperature 16 However, it is not clear, whether the predicted high magnetoresistance effects were not seen because the materials are contrary to predictions not half-metals or owing to the tunnel junction properties. Especially the pronounced reduction of the magnetoresistances at room temperature is surprising, because the Curie temperatures of Heusler compounds can approach 1,000 K (for example, Co 2 MnSi 20,21 ).