Control via electron count of the competition between magnetism and superconductivity in cobalt and nickel doped NaFeAs

Using a combination of neutron, muon and synchrotron techniques we show how the magnetic state in NaFeAs can be tuned into superconductivity by replacing Fe by either Co or Ni. Electron count is the dominant factor, since Ni-doping has double the effect of Co-doping for the same doping level. We follow the structural, magnetic and superconducting properties as a function of doping to show how the superconducting state evolves, concluding that the addition of 0.1 electrons per Fe atom is sufficient to traverse the superconducting domain, and that magnetic order coexists with superconductivity at doping levels less than 0.025 electrons per Fe atom.Comment: 4 pages, 6 figure

Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs.

A new layered iron arsenide NaFeAs isostructural with the superconducting lithium analogue, displays evidence for the coexistence of superconductivity and magnetic ordering.Comment: 3 pages, 4 figures + supplementary information. Version 2 contains additional muon-spin rotation dat

The Interactive Dynamics of Transnational Business Governance: A Challenge for Transnational Legal Theory

Conflict, convergence, cooperation, competition and other interactions among governance actors and institutions have long fascinated scholars of transnational law, yet transnational legal theorists’ accounts of such interactions are for the most part tentative, incomplete and unsystematic. Having elsewhere proposed an overarching conceptual framework for the study of transnational business governance interactions (TBGI), in this article we propose criteria for middle-range theory-building. We argue that a portfolio of theoretical perspectives on transnational governance interactions should account for the multiplicity of interacting entities and scales of interaction; the co-evolution of social agency and structure; the multiple components of regulatory governance; the role of interactions as both influence and outcome; the diverse modes of interaction; the mechanisms and pathways of interaction; and the spatiotemporal dynamics of interaction. To suggest the value of these criteria, we apply them in a preliminary way to selected transnational legal scholarship and to the other articles in this special issue of Transational Legal Theory