Magnetic phase transitions in Ta/CoFeB/MgO multilayers

We study thin films and magnetic tunnel junction nanopillars based on Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO multilayers by electrical transport and magnetometry measurements. These measurements suggest that an ultrathin magnetic oxide layer forms at the Co$_{20}$Fe$_{60}$B$_{20}$/MgO interface. At approximately 160 K, the oxide undergoes a phase transition from an insulating antiferromagnet at low temperatures to a conductive weak ferromagnet at high temperatures. This interfacial magnetic oxide is expected to have significant impact on the magnetic properties of CoFeB-based multilayers used in spin torque memories

Kinds of well-being: A conceptual framework that provides direction for caring

This article offers a conceptual framework by which different kinds and levels of well-being can be named, and as such, provides a foundation for a resource-oriented approach in situations of illness and vulnerability (rather than a deficit-oriented approach). Building on a previous paper that articulated the philosophical foundations of an existential theory of well-being (“Dwelling-mobility”), we show here how the theory can be further developed towards practice-relevant concerns. We introduce 18 kinds of well-being that are intertwined and inter-related, and consider how each emphasis can lead to the formulation of resources that have the potential to give rise to well-being as a felt experience. By focusing on a much wider range of well-being possibilities, practitioners may find new directions for care that are not just literal but also at an existential level

Caring Leadership: A Heideggerian Perspective

This paper develops the idea of caring leadership based on Heidegger’s philosophy of care. From this perspective, caring leadership is grounded in the practices of ‘leaping-in’ and ‘leaping-ahead’ as modes of intervention in the affairs of the world and the efforts of others. This involves gauging and taking responsibility for the ramifications of intervention, balancing the urge for certainty of outcome and visibility of contribution with the desire to encourage and enable others. Our analysis suggests several twists to contemporary leadership debates. We argue that the popular models of transactional and transformational leadership are to be critiqued not for their over-reliance, but rather, their under-reliance on agency. This is a different kind of agency to that of heroic or charismatic models. It involves tolerance of complexity and ambivalence; a rich sense of temporal trajectory; concern for one’s presence in the world; and crucially, the ability to resist the soothing normativity of ‘best practice’. From this position, we argue that the problem with the growing scholarly interest in an ethic of care is that it provides too tempting a recipe to follow. In a Heideggerian view, caring leadership has little to do with compassion, kindness or niceness; it involves and requires a fundamental organization and leadership of self

"Outside, it is snowing": Experience and finitude in the nonrepresentational landscapes of Alain Robbe-Grillet

Copyright © 2008 PionRomanillos J L, 2008. The definitive, peer-reviewed and edited version of this article is published in Environment and Planning D: Society and Space 26(5) 795 – 822 DOI: 10.1068/d6207This paper presents and explicates the anonymous and impersonal spatialities tentatively mapped in the novels of Alain Robbe-Grillet. Emerging from the kinds of landscapes and visualities articulated, these spatialities are at odds with the kind of anthropocentrism characteristic of phenomenological narratives of spatial experience that would start from an apparently stable human-subject position. It is argued that his body of literature dismantles the anthropocentric narratives and biographies that would produce in both the space of the world and the ‘phenomenological subject’ an unwarranted depth and naturalism. Importantly, and reflecting the theoretical turn towards the being of language, Robbe-Grillet questions the legitimacy of linguistic subjects to capture the spaces of the visible. As such, it is argued that his literature reflects an experience of the critiques of phenomenology. Importantly, this ‘critique’ goes hand in hand with the kinds of spatialities and landscapes that are rendered in the novels—the indefinite perspectives they open up, the paradoxical visualities they sustain or deny, and the disorientation they inject into the heart of spatial experience. These literary effects produce a nonanthropocentric and nonpersonal spatiality which, although contributing to an erasure of the ‘subject’, at the same time expose and open up a sociospatiality based on singularities, intensities, and finitude

Multimaterial 4D Printing with Tailorable Shape Memory Polymers

We present a new 4D printing approach that can create high resolution (up to a few microns), multimaterial shape memory polymer (SMP) architectures. The approach is based on high resolution projection microstereolithography (PμSL) and uses a family of photo-curable methacrylate based copolymer networks. We designed the constituents and compositions to exhibit desired thermomechanical behavior (including rubbery modulus, glass transition temperature and failure strain which is more than 300% and larger than any existing printable materials) to enable controlled shape memory behavior. We used a high resolution, high contrast digital micro display to ensure high resolution of photo-curing methacrylate based SMPs that requires higher exposure energy than more common acrylate based polymers. An automated material exchange process enables the manufacture of 3D composite architectures from multiple photo-curable SMPs. In order to understand the behavior of the 3D composite microarchitectures, we carry out high fidelity computational simulations of their complex nonlinear, time-dependent behavior and study important design considerations including local deformation, shape fixity and free recovery rate. Simulations are in good agreement with experiments for a series of single and multimaterial components and can be used to facilitate the design of SMP 3D structures

Angular dependence of superconductivity in superconductor/spin-valve heterostructures

We report measurements of the superconducting transition temperature, Tc, in CoO/Co/Cu/Co/Nb multilayers as a function of the angle α between the magnetic moments of the Co layers. Our measurements reveal that Tc(α) is a nonmonotonic function, with a minimum near α=π/2. Numerical self-consistent solutions of the Bogoliubov-de Gennes equations quantitatively and accurately describe the behavior of Tc as a function of α and layer thicknesses in these superconductor/spin-valve heterostructures. We show that experimental data and theoretical evidence agree in relating Tc(α) to enhanced penetration of the triplet component of the condensate into the Co/Cu/Co spin valve in the maximally noncollinear magnetic configuration. © 2014 American Physical Society