Slater-Pauling Behavior of the Half-Ferromagnetic Full-Heusler Alloys

Using the full-potential screened Korringa-Kohn-Rostoker method we study the full-Heusler alloys based on Co, Fe, Rh and Ru. We show that many of these compounds show a half-metallic behavior, however in contrast to the half-Heusler alloys the energy gap in the minority band is extremely small. These full-Heusler compounds show a Slater-Pauling behavior and the total spin-magnetic moment per unit cell (M_t) scales with the total number of valence electrons (Z_t) following the rule: M_t=Z_t-24. We explain why the spin-down band contains exactly 12 electrons using arguments based on the group theory and show that this rule holds also for compounds with less than 24 valence electrons. Finally we discuss the deviations from this rule and the differences compared to the half-Heusler alloys.Comment: 10 pages, 8 figures, revised figure 3, new text adde

Magnetic properties of Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition

Polycrystalline Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition are studied by differential scanning calorimetry, magnetic and resistivity measurements. Coupling of the magnetic and structural subsystems results in unusual magnetic features of the alloy. These uncommon magnetic properties of Ni2.18Mn0.82Ga are attributed to the first-order structural transition from a tetragonal ferromagnetic to a cubic paramagnetic phase.Comment: 4 pages, 4 figures, revtex

Splitting of the Cr 2p ions states in some ternary sulphides and selenides

PACS. 79.60.-i Photoemission and photoelectron spectra - 75.50.Pp Magnetic semiconductors,

New data about the consumption of fish from the Alsace Region, France

International audienceThis study provides an overview of 11 archaeological sites that yielded fish boneremains from the Roman period through medieval to modern contexts. It bringsnew knowledge about the consumption of fish for the Alsace region. Although thenumbers of remains vary greatly, some diachronic comparisons are possible. Themajority of the species represented in the assemblages from the inland sites sampledwere freshwater fishes, together with a few migratory fishes. Most individuals weresmall‐sized fishes, which may explain the type of structure analysed, for instance,latrines. Two wels catfish vertebrae indicate the presence of this species in France.European marine fishes such as cod and flatfish are very rare, and the importationof marine fish began more recently. However, some herring bones found in theRoman and early medieval period make a straightforward interpretation moredifficult

Descent with modification and the archaeological record

Recent years have seen major advances in our understanding of the way in which cultural transmission takes place and the factors that affect it. The theoretical foundations of those advances have been built by postulating the existence of a variety of different processes and deriving their consequences mathematically or by simulation. The operation of these processes in the real world can be studied through experiment and naturalistic observation. In contrast, archaeologists have an ‘inverse problem’. For them the object of study is the residues of different behaviours represented by the archaeological record and the problem is to infer the microscale processes that produced them, a vital task for cultural evolution since this is the only direct record of past cultural patterns. The situation is analogous to that faced by population geneticists scanning large number of genes and looking for evidence of selection as opposed to drift, but more complicated for many reasons, not least the enormous variety of different forces that affect cultural transmission. This paper reviews the progress that has been made in inferring processes from patterns and the role of demography in those processes, together with the problems that have arisen