Estimation of the experimental standard deviations in EXAFS measurements

被引：18

作者：

Vlaic, G

Andreatta, D

Cepparo, A

Colavita, PE

Fonda, E

Michalowicz, A

机构：

[1] Univ Trieste, Dipartimento Sci Chim, I-34127 Trieste, Italy

[2] Sincrotrone Trieste, Elettra, I-34012 Trieste, Italy

[3] Univ Paris 12, GPMD, F-94010 Creteil, France

来源：

JOURNAL OF SYNCHROTRON RADIATION | 1999年 / 6卷

关键词：

statisitcs; standard deviation; exafs error bars;

D O I：

10.1107/S0909049599000722

中图分类号：

TH7 [仪器、仪表];

学科分类号：

0804 ; 080401 ; 081102 ;

摘要：

We have studied the multiple recording method to estimate if it possible to obtain by this way reliable EXAFS data standard deviations. The examination of more than 10 different samples, each of them recorded at least 8 times, gave us the possibility to show that the partial standard deviations follow the expected probability laws. Even when the number of samples is small, it is possible to give a reasonable upper limit of epsilon which could be used as the statistical contribution of the experimental error bars. In some cases we have found that a uniform weighting by 1/epsilon(2) may fail to give a good fit, especially in the high part of k space. We present a simple method of weighting which lead to more satisfying fits without loosing the correct normalisation of the fined Delta chi(2) necessary to obtain correct fitted parameters error bars.

引用

页码：225 / 227

页数：3