Title

Correlates Of Multiple Placements In Foster Care: A Study Of Placement Instability In Five States

Keywords

Aluminum; Impurity diffusivity; Magnesium; Secondary ion mass spectroscopy

Abstract

The diffusion of Al in polycrystalline Mg (99.9%) was studied via depth profiling with secondary ion mass spectrometry in the temperature range of 573-673 K, utilizing the thin film method and thin film solution to the diffusion equation. Multiple samples with multiple depth profiles on each sample were obtained to determine statistically confident coefficients with a maximum standard deviation between measurements of 16%. The activation energy and pre-exponential factor of Al impurity diffusion in Mg were determined as 155 kJ/mole and 3.9×10 -23 m 2/s, respectively. The Mg substrates have a small grain size (∼10 μm) and therefore some contributions from grain boundary diffusion are expected in the measurements. Sputter roughening during depth profiling, which is inherent to the SIMS process, also contributes to the measured diffusion coefficient, especially in samples with smaller grain sizes. © ASM International.

Publication Date

4-1-2012

Publication Title

Journal of Public Child Welfare

Volume

6

Issue

2

Number of Pages

172-190

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1080/15548732.2012.667734

Socpus ID

84861303359 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84861303359

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