25 research outputs found

    Rare earth magnetism in CeFeAsO: A single crystal study

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    Single crystals of CeFeAsO, large enough to study the anisotropy of the magnetic properties, were grown by an optimized Sn-flux technique. The high quality of our single crystals is apparent from the highest residual resistivity ratio, RRR = 12, reported among undoped RFeAsO compounds (R=rare earth) as well as sharp anomalies in resistivity, specific heat, C(T), and thermal expansion at the different phase transitions. The magnetic susceptibility chi(T) presents a large easy-plane anisotropy consistent with the lowest crystal electric field doublet having a dominant Gamma_6 character. Curie-Weiss like susceptibilities for magnetic field parallel and perpendicular to the crystallographic c-axis do not reveal an influence of a staggered field on the Ce site induced by magnetic ordering of the Fe. Furthermore, the standard signatures for antiferromagnetic order of Ce at T_N = 3.7 K observed in chi(T) and C(T) are incompatible with a Zeeman splitting Delta = 10 K of the CEF ground state doublet at low temperature due to the Fe-magnetic order as previously proposed. Our results can be reconciled with the earlier observation by assuming a comparatively stronger effect of the Ce-Ce exchange leading to a reduction of this Zeeman splitting below 15 K.Comment: 15 pages, 6 figures, added section on magn. susceptibilit

    Re-imagining the growth process: (co)-evolving metaphorical representations of entrepreneurial growth

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    We investigate the role and influence of the biological metaphor ‘growth’ in studies of organizations, specifically in entrepreneurial settings. We argue that we need to reconsider metaphorical expressions of growth processes in entrepreneurship studies in order to better understand growth in the light of contemporary challenges, such as environmental concerns. Our argument is developed in two stages: first, we review the role of metaphor in organization and entrepreneurship studies. Second, we reflect critically on three conceptualizations of growth that have drawn on biological metaphors: the growing organism, natural selection and co-evolution. We find the metaphor of co-evolution heuristically valuable but under-used and in need of further refinement. We propose three characteristics of the co-evolutionary metaphor that might enrich our understanding of entrepreneurial growth: relational epistemology; collectivity; and multidimensionality. Through this we provide a conceptual means of reconciling an economic impetus for entrepreneurial growth with an environmental imperative for sustainability

    Re-inventing artisanal knowledge and practice: a critical review of innovation in a craft-based industry

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    This paper presents a critical review of the ways in which the specialised knowledge and working practices of craft-based industries have been transformed in the context of broader processes of industrialisation and global competition. The opening section makes the case for artisanal knowledge as a ‘Cinderella’ subject that remains important yet largely uncharted territory for innovation researchers. It is followed by a critical review of existing empirical and theoretical studies that have examined the reproduction and reinvention of artisanal knowledge. The review concludes that valuable insights remain obscured due to the way in which this literature is distributed across discrete disciplines with little evidence of cross-fertilisation or integration. Several common themes emerge, which provide the basis for an outline theoretical framework. The central arguments are illustrated with reference to a case-based analysis of the technological and social innovations that have taken place in English farmhouse cheesemaking over an extended period, from the pre-industrial era to the beginning of the present century. The concluding section considers how more nuanced understandings of artisanal knowledge and practice might enhance innovation theory and contribute to the continued flourishing of craft-based industries

    'Little Ships': The Co-evolution of Technological Capabilities and Industrial Dynamics in Competing Innovation Networks

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    Recent agenda-setting exercises in the national innovation systems and industrial dynamics literatures have highlighted the unresolved methodological challenges faced by those seeking to explore the innovation process in a co-evolutionary perspective. The paper seeks to contribute to this debate by drawing upon the research methods and presentational conventions of business historians. The empirical study concerns the emergence of radical innovations in the design and manufacture of sailing dinghies in mid-20th-century Britain. This period saw the displacement of small, highly localized firms engaged in traditional craft practices by a new generation of designers, manufacturers and promoters in pursuit of volume production. The findings are presented in the form of a historical narrative, contrasting the configurations and dynamics of two competing innovation networks in this sector. It shows how actors in each network drew differently on newly available platform technologies, probes their distinctive approaches to design, manufacturing and marketing, and assesses their longer-term impact on the sector. The concluding section relates the findings to the previously discussed theoretical constructs and reflects on the potential contribution of historically informed methodologies.Co-evolution, historical method, industrial dynamics, innovation networks, technological capabilities,
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