X-ray diffraction from dislocation half-loops in epitaxial films

X-ray diffraction from dislocation half-loops consisting of a misfit segment and two threading arms extending from it to the surface is calculated by the Monte Carlo method. The diffraction profiles and reciprocal space maps are controlled by the ratio of the total lengths of the misfit and the threading segments of the half-loops. A continuous transformation from the diffraction characteristic of misfit dislocations to that of threading dislocations with increasing thickness of an epitaxial film is studied. Diffraction from dislocations with edge and screw threading arms is considered and the contributions of both types of dislocations are compared

Responding to the (almost) unknown: Social representations and corporate policies of social media

End-user driven technologies, such as social media, have dramatically changed organizations’ innovation processes. In these new contexts, organizational decision makers have to contend with a de facto adoption of new technologies that they have yet to understand fully. In order to contribute to the understanding of these new contexts and their implications for organizations and their decision makers, this paper examines the following question: How do organizations come to comprehend and react to end-user driven technologies? Conceptually based on social representations theory, this paper underscores how organizational decision-makers develop common sense knowledge of end-user driven technologies and how they consequently endorse responses in the form of dedicated policies that reflect this knowledge. This theoretical framework helps us interpret the empirical analysis of 25 corporate social media policies. The paper shows that, in developing their understanding of social media, so far organizational decision-makers have mostly associated them with what was already familiar to them and have devised policies that have reflected this mostly conservative understanding of the new technologies. Implications of this research include a better understanding of the foundation of the duality between mindful and mindless innovations in the context

Ostwald ripening of faceted two-dimensional islands

We study Ostwald ripening of two-dimensional adatom and advacancy islands on a crystal surface by means of kinetic Monte Carlo simulations. At large bond energies the islands are square-shaped, which qualitatively changes the coarsening kinetics. The Gibbs--Thomson chemical potential is violated: the coarsening proceeds through a sequence of `magic' sizes corresponding to square or rectangular islands. The coarsening becomes attachment-limited, but Wagner's asymptotic law is reached only after a very long transient time. The unusual coarsening kinetics obtained in the Monte Carlo simulations are well described by the Becker--Döring equations of nucleation kinetics. These equations can be applied to a wide range of coarsening problems

Mapping Perceptions of Burnout in the Information Technology Profession: A Study Using Social Representations Theory

Job-related burnout in information technology professionals is seen as a serious issue for organizations and individuals. While the substantial body of research on job stress and burnout can provide valuable insights into the prevention of burnout in IT as well as interventions, we argue that drawing upon this work should be done with caution. In particular, generalizability of the learnings beyond the occupations studied (predominantly people-oriented and/or caregiving roles) cannot be assumed. As a first step toward assessing the applicability of existing burnout research to IT, the purpose of the study described in this paper is to understand how IT professionals make sense of and assign meaning to burnout in the profession. The study uses an approach based on social representations theory, which was first formulated by French social psychologist Serge Moscovici. Social representations are defined as the shared images and concepts through which we organize our world. Transcripts from in-depth interviews of 20 IT professionals were content- analyzed and 22 key topics (concepts) identified. Quantitative methods (including analysis of similarity and analyses to determine the relational structure of the concepts) were used to create a social representations map of these professionals’ understandings of burnout. The map provides preliminary evidence of elements that are central/peripheral to those understandings, pointing to implications for the applicability of existing theory on burnout as well as priorities for future research

Bunches of misfit dislocations on the onset of relaxation of Si0.4_{0.4}Ge0.6_{0.6}/Si(001) epitaxial films revealed by high-resolution x-ray diffraction

The experimental x-ray diffraction patterns of a Si$_{0.4}$Ge$_{0.6}$/Si(001) epitaxial film with a low density of misfit dislocations are modeled by the Monte Carlo method. It is shown that an inhomogeneous distribution of 60$^\circ$ dislocations with dislocations arranged in bunches is needed to explain the experiment correctly. As a result of the dislocation bunching, the positions of the x-ray diffraction peaks do not correspond to the average dislocation density but reveal less than a half of the actual relaxation