GB/T 37054-2018Nanotechnology—Testing ratio of anatase to rutile in nano-titanium dioxide—X-ray diffraction (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This standard specifies the principle of the method for determining the ratio of anatase crystal form to rutile crystal form in nanometer titanium dioxide by X-ray diffraction method. Instruments, reference samples, sample preparation, analysis steps, results calculations, and results reporting.

This standard applies to nanometer titanium dioxide powder containing anatase and rutile crystal form with a purity of not less than 99%.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

JJG629 polycrystalline X-ray diffractometer verification procedures

JJF1059.1-2012 Measurement uncertainty evaluation and representation

3 Principle

The crystal has a characteristic X-ray diffraction pattern. The intensity of a diffraction peak caused by one component in a mixture composed of a plurality of crystals Depending on the amount of this component in the mixture, the peak intensity of a component also depends on the mass absorption coefficient of the other components.

For a mixture of N phases, the intensity Ij of one of the diffraction lines of the jth term is satisfied with its mass fraction mj The following formula (1).

In the formula.

Kj --- the intrinsic constant of a diffraction line of the jth phase;

Mj --- the mass fraction of the jth phase;

rhoj --- the density of the jth phase;

Mm --- mass absorption coefficient of the mixture.

For a certain phase in the mixture, Kj and rhoj in the formula (1) are inherent constants, and the formula (1) can be simplified to the following formula (2).

K is related to the parameters of diffraction geometry, physical constant, and the nature of the phase of the measured object. It can be seen that K is a constant change. The number is only a constant after the phase of the measured object and the experimental conditions of the diffraction are determined.

Titanium dioxide powder composed of anatase and rutile, since anatase and rutile are isomers, their mass absorption coefficients The same, therefore, there is a mass absorption coefficient µm of the titanium dioxide sample µm=mAµmA mRµmR=µmA=µmR. By the formula (2) at this time anatase or The diffraction line intensities of rutile are of formula (3) and formula (4).