Reaction kinetics and phase diagram studies in the Ti-Zn system

Ti-Zn phase diagram and layers growth kinetics, have been studied at 500, 600 and 900degreesC. Linear growth has been observed. The calculated values of the growth constants K-G are: at 500degreesC, K-G = (7.5 +/- 0.3) x 10(-9) m s(-1); at 600 degreesC, K-G = (8.0 +/- 0.2) x 10(-9) m s(-1). An indication about the presence of a formerly unknown compound (Ti2Zn3) has been found out by electron microprobe analyses and optical microscopy. Homogeneity ranges (probably metastable) have been observed for some phases that are considered to be stoichiometric. (C) 2003 Elsevier B.V. All rights reserved

Thermodynamic assessments of the Cu-Mn-X (X : Fe, Co) systems

通讯作者地址: Liu, XJ (通讯作者), Xiamen Univ, Coll Chem & Chem Engn, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, Dept Mat Sci & Engn, Xiamen 361005, Peoples R China 2. Tohoku Univ, Grad Sch Engn, Dept Mat Sci, Sendai, Miyagi 9808579 Japan 电子邮件地址: [email protected] thermodynamic assessments of the Cu-Mn binary, Cu-Mn-Fe and Cu-Mn-Co ternary systems were carried out by using CALPHAD (calculation of phase diagrams) method on the basis of the experimental data including the thermodynamic properties and phase equilibria. The Gibbs free energies of the liquid, bcc, fcc, hep, (alpha Mn) and (beta Mn) phases are described by the subregular solution model. The thermodynamic parameters of the Cu-Mn binary, Cu-Mn-Fe and Cu-Mn-Co ternary systems have been optimized for reproducing the experimental results in each system, respectively. An agreement between the calculated results and experimental data is obtained. (C) 2006 Published by Elsevier B.V

Effect of Specimen Bias on the Contrast of High Resolution Low Voltage SEM Images in a Semi-In-Lens JSM-6320f Fe-SEM

Nanometer-resolution surface imaging by secondary electrons (SE) is now routinely obtainable in field-emission SEM or STEM microscopes. The resolution in SE images obtained in a modern field-emission (FE) SEM is still limited by the electron probe size although the localization of the SE generation processes sets the ultimate resolution limit that will be achievable in SE images. The combination of a FE gun with improved probe forming lenses and detection systems makes it possible to image nanometer-scale surface features at low voltages. Because of the reduced electron beam range and the new SE detection system, image contrast formation in low voltage FE-SEMs is quite different to that in conventional SEMs. In a FE-SEM, SEs are detected through the combination of a strong magnetic field of the lens and a weak electrostatic extraction field of the detector. The detection efficiency varies with the energy of the emitted SEs.</jats:p