Carbon nanotube synthesis from germanium nanoparticles on patterned substrates

Controlled synthesis of carbon nanotubes (CNTs) is highly desirable for nanoelectronic applications. To date, metallic catalyst particles have been deemed unavoidable for the nucleation and growth of any kind of CNTs. Ordered arrays of nanotubes have been obtained by controlled deposition of the metallic catalyst particles. However, the presence of metal species mixed with the CNTs represents a shortcoming for most electronic applications, as metal particles are incompatible with silicon semiconductor technology. In the present paper we report on a metal-catalyst-free synthesis of CNTs, obtained through Ge nanoparticles on a Si(001) surface patterned by nanoindentation. By using acetylene as the carbon feed gas in a low-pressure Chemical Vapor Deposition (CVD) system, multi-walled carbon nanotubes (MWNT) have been observed to arise from the smallest Ge islands. The CNTs and the Ge three-dimensional structures have been analysed by SEM, EDX and AFM in order to assess their elemental features and properties. EDX and SEM results allow confirmation of the absence of any metallic contamination on the surface, indicating that the origin of the CNT growth is due to the Ge nanocrystals.

Indigenous men's support groups and social and emotional wellbeing : a meta-synthesis of the evidence

Indigenous men’s support groups are designed to empower men to take greater control and responsibility for their health and wellbeing. They provide health education sessions, counselling, men’s health clinics, diversionary programs for men facing criminal charges, cultural activities, drug- and alcohol-free social events, and advocacy for resources. Despite there being ~100 such groups across Australia, there is a dearth of literature on their strategies and outcomes. This paper is based on participatory action research involving two north Queensland groups which were the subject of a series of five ‘phased’ evaluative reports between 2002 and 2007. By applying ‘meta-ethnography’ to the five studies, we identified four themes which provide new interpretations of the data. Self-reported benefits included improved social and emotional wellbeing, modest lifestyle modifications and willingness to change current notions of ‘gendered’ roles within the home, such as sharing housework. Our qualitative research to date suggests that through promoting empowerment, wellbeing and social cohesion for men and their families, men’s support groups may be saving costs through reduced expenditure on health care, welfare, and criminal justice costs, and higher earnings. Future research needs to demonstrate this empirically.

Synthesis and thermal analysis of Indium based hydrotalcites of formula Mg6In2(CO3)(OH)16•4H2O

Insight into the unique structure of layered double hydroxides has been obtained using a combination of X-ray diffraction and thermal analysis. Indium containing hydrotalcites of formula Mg4In2(CO3)(OH)12•4H2O (2:1 In-LDH) through to Mg8In2(CO3)(OH)18•4H2O (4:1 In-LDH) with variation in the Mg:In ratio have been successfully synthesised. The d(003) spacing varied from 7.83 Å for the 2:1 LDH to 8.15 Å for the 3:1 indium containing layered double hydroxide. Distinct mass loss steps attributed to dehydration, dehydroxylation and decarbonation are observed for the indium containing hydrotalcite. Dehydration occurs over the temperature range ambient to 205 °C. Dehydroxylation takes place in a series of steps over the 238 to 277 °C temperature range. Decarbonation occurs between 763 and 795 °C. The dehydroxylation and decarbonation steps depend upon the Mg:In ratio. The formation of indium containing hydrotalcites and their thermal activation provides a method for the synthesis of indium oxide based catalysts.