48 research outputs found

    Spin-fluctuation theory beyond Gaussian approximation

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    A characteristic feature of the Gaussian approximation in the functional-integral approach to the spin-fluctuation theory is the jump phase transition to the paramagnetic state. We eliminate the jump and obtain a continuous second-order phase transition by taking into account high-order terms in the expansion of the free energy in powers of the fluctuating exchange field. The third-order term of the free energy renormalizes the mean field, and fourth-order term, responsible for the interaction of the fluctuations, renormalizes the spin susceptibility. The extended theory is applied to the calculation of magnetic properties of Fe-Ni Invar.Comment: 20 pages, 4 figure

    Aboriginal and Torres Strait Islander Suicide in Context

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    Aboriginal and Torres Strait Islander suicide has been an issue of national public health and mental health concern for only one decade, having increased dramatically from levels that were very low in the late 1980s to levels of young adult male suicide that are now substantially higher than for the non-indigenous population. In this review the authors socially and historically contextualize these changes, identifying the causal frameworks adopted in developing interventions, and present an explanation in narrative and pictorial form that draws on critical family-centered trauma

    More important than guns or grog: The role of television for the health and wellbeing of Australian Aboriginal prisoners

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    Published online: 30 Nov 2018This article examines the provision of television in the South Australian prison system and its importance to the identity, health, wellbeing and ontological security of Aboriginal prisoners. Existing research has explored the use of broadcast and print media by prisoners in the United Kingdom, United States and Europe and has established that television has an impact on incarcerated audiences far beyond its role as an ‘electronic babysitter’ or a means of filling time. It is also recognised that television plays a significant role in the lives of Aboriginal people (Michaels 1986). However, little is known about television in relation to incarcerated Aboriginal and Torres Strait Islander Australians. This article draws on data concerning in-cell television (‘TV’) among Aboriginal men in prison,1 which found that, when asked to identify the most important factors in the prison environment, 87 per cent of participants identified access to in-cell television as the single most important factor contributing to their congruency with prison accommodation. The article further indicates that access to in-cell television has the potential to reduce incidents of suicide and self-harm and should be adopted as a ‘best-practice’ principle for Aboriginal prisoners in Australian correctional environments.Elizabeth Grant and Yvonne Jewkeshttp://heinonline.org/HOL/Index?index=journals/cicj&collection=journal

    Dynamic spin-fluctuation theory of metallic magnetism

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    This book presents a theoretical framework for magnetism in ferromagnetic metals and alloys at finite temperatures. The objective of the book is twofold. First, it gives a detailed presentation of the dynamic spin-fluctuation theory that takes into account both local and long-wave spin fluctuations with any frequency. The authors provide a detailed explanation of the fundamental role of quantum spin fluctuations in the mechanism of metallic magnetism and illustrate the theory with concrete examples. The second objective of the book is to give an accurate and self-contained presentation of many-body techniques such as the functional integral method and Green's functions, via a number of worked examples. These computational methods are of great use to solid state physicists working in a range of specialties. The book is intended primarily for researchers, but can also be used as textbook. The introductory chapters offer clear and complete derivations of the fundamentals, which makes the presentation self-contained. The main text is followed by a number of well-organized appendices that contain a detailed presentation of the necessary many-body techniques and computational methods. The book also includes a list of symbols and detailed index. This volume will be of interest to a wide range of physicists interested in magnetism and solid state physics in general, both theoreticians and experimentalists

    Spin-Density Correlations and Short-Range Order in Metals above the Curie Temperature

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    In the dynamic spin-fluctuation theory, we calculate the effective and local magnetic moments and spatial spin-density correlator. Our theoretical results are demonstrated by the example of bcc Fe. The effective and local moments are found in good agrement with results of polarized neutron scattering experiment over a wide temperature range. The calculated short-range order is small (up to 5 Ã…) and slowly decreases with temperatur

    Spin-Density Correlations and Short-Range Order in Metals above the Curie Temperature

    No full text
    In the dynamic spin-fluctuation theory, we calculate the effective and local magnetic moments and spatial spin-density correlator. Our theoretical results are demonstrated by the example of bcc Fe. The effective and local moments are found in good agrement with results of polarized neutron scattering experiment over a wide temperature range. The calculated short-range order is small (up to 5 Ã…) and slowly decreases with temperatur
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