Use of a phenomenological chemical scale for the identification of high distribution coefficient impurities within the ITS-90

4th International Conference on Advances in Solidification Processes

材料科学;物理学

Lowe, D.H.^1

National Physical Laboratory, Teddington, United Kingdom^1

关键词: Distribution coefficient;    Impurities in;    International Temperature Scale of 1990;    Pure metals;    Quantum mechanical;    Reproducibilities;    Resonance peak;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/117/1/012026/pdf
DOI  :  10.1088/1757-899X/117/1/012026

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The International Temperature Scale of 1990 standardises practical temperature measurement based on the reproducibility of the solidification phase transition temperature of highly pure metals. The effect of impurities can be the biggest block to establishing international equivalence of temperature metrology and so it is important to have knowledge of the distribution coefficients for all potential impurities. In particular impurities with a high distribution coefficient cause problems with applying corrections, and so it is helpful to identify which impurities are likely to be an issue. By plotting the published measured distribution coefficients of impurities in the metals used as references in the International Temperature Scale of 1990, as a function of a quantum mechanical based scale intended to provide separation of binary alloy crystal structure, an apparent resonance peak is found. This could allow a simple fit equation to be applied to determine whether a given impurity is likely to cause an error to any correction strategy.