Size Dependence of a Temperature-Induced Solid–Solid Phase Transition in Copper(I) Sulfide

Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid-solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase trans- formations suggests the possibility of accessing morphologies that are not found in bulk solids at ambient conditions. These other- wise-inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics

Os acordes de Yes we can do vídeo da campanha presidencial de Barak Obama The Yes we can chords

Estudo sobre o loop de quatro acordes &#9553;: Sol Maior - Si Maior - Mi Menor - Dó Maior :&#9553; na canção Yes we can [Sim, nós podemos] do vídeo de Will.i.am (ADAMS, 2008) lançado durante a campanha presidencial de Barack Obama nos Estados Unidos. A partir da identificação de IOCMs (Materiais Interobjetivos de Comparação) e PMFCs (Campos Paramusicais Conotativos) da análise musemática (TAGG, 2009), compara-se Yes we can com materiais harmônicos, melódicos, rítmicos, de instrumentação e de letras de canções populares da tradição afro-britânico-americana, levando-se também em consideração as atitudes de relevantes compositores e intérpretes populares social e politicamente engajados.<br>Study of the four-chord loop &#9553;: G - B - Em - C :&#9553; in the song Yes We Can from the video by Will.i.am (ADAMS, 2008) released during the 2008 US presidential campaign of Barack Obama. Departing from IOCM and PMFC identification of the musematic analysis (TAGG, 2009), Yes We Can is compared to harmony, melody, rhythm, instrumentation and lyrics found in iconic popular songs of the Afro-Bristish-American tradition, also taking into consideration the attitudes of relevant composers and performers engaged in social and political issues