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X-RAY DEFFRACTROMETRY FORQUALITATIVE ANALYSIS OF

MATERIALS

INSTRUCTED BY: Dr. JAYARATHNA M.

PARTNERS

1. KUMARA R.S.C.K

2. LIYANARACHCHI K.N

3. MADURANGA L.B.W.R

4. PRASATH T

5. PULLE V.A.S.A

6. PERERA R.A.D

NAME: MADURAPPERUMA C

COURSE: MT

GROUP: C

DATE OF PRE: 28/10/2010

DATE OF SUB: 30/11/2010


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TITLE: X-RAY DEFFRACTROMETRY FOR QUALITATIVE ANALYSIS OFMATERIALS

INTRODUCTION:

Analysis of a crystalline material using X ray diffraction patterns has become an

extremely useful method of material analysis. The main X ray diffraction methods used toidentify materials are,

(1) Laue method (Transmission method, Back reflection method)

(2) Rotating crystal method

(3) Powder method (Debye-Schrrer camera method, Diffractometer method)

During this practical, an attempt was made to identify a ceramic material using the

Diffractometer method.

THEORY:

X rays that are being deflected off two parallel planes can either be superimposed

constructively or destructively as shown below.

For first order constructive diffraction,

= 2dsin

MATERIALS AND APPARATUS:

Apparatus: X-ray diffractometer

Glass plate

Materials: Ceramic powder sample


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PROCEDURE:

The ceramic sample was prepared to powder specimen of a size less than

10microns.

The specimen was then prepared by placing the powder in the recess of the

glass plate compacting it with enough pressure to cause cohesion betweenthe powder and the glass plate.

Then the surface was smoothened off.

The slide was then fixed on the sample holder of the X ray diffractometer

and the scanning unit was moved continuously over a circular scale and the

variation of intensity was obtained against the changing angle on a strip

chart.

CALCULATIONS:

= 1.5418

Imax= I4 = 150= 150

Intensity for I2 th peak = 31100% = 20.67%100

d value for I2 th peak = 1.5418__ = 4.25036 2sin(20.9/2)

Peak no.(Ii) 2 Intensity (%)d = __ ()

2sinI1 26.6 100 3.351101I2 20.9 20.67 4.25036I3 36.6 12.67 2.45521I4 50.2 11.34 1.81735I5 60 8 1.87184I6 39.4 7 2.28694I7 68 6.67 1.37862I8 46.8 4.67 1.94114I9 42.5 4.34 2.12703I10 40.25 4 2.24059I11 54.9 4 1.67237

I12 64.2 2.67 1.45073I13 55.4 1.34 1.65845

RESULTS:

From the Hanwalt manual and the JCPPS card, the minerals that closely matchedthe given sample is closed to Genkinite mineral.


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DISCUSSION:

We can get the maximum 3 peaks as I4, I7 & I9 . They have d values of 3.018, 2.276& 1.907.

In the genkinite, it has maximum intensity d values of 3.02, 2.27 & 1.93.In the chalcocite-high, it has maximum intensity d values of 3.05, 2.40 & 1.98.

In the stetefeldtite, it has maximum intensity d values of 3.02, 2.61 & 1.85.

Therefore firstly we can approximate the genkinite {(Pt,Pb)4Sb3}as prepared sample.

Our 2 Vs intensity graph has 14 peaks. But chart has only 8d values. Except

above 3 values, it has 5d values (1.91, 0.9, 2.15, 2.12, 1.27). Above observation tablegives other values for practical intensities.

It can also be seen that in most of the d values for both quartz and Berlinite, theexpected values for intensity are half of that of the obtained values. This may occur due toseveral reasons such as using a powder which contains a considerable no of particleswhose size is greater than 10 microns, mixing of other impurity materials that have dvalues as those in which the intensity has shown a considerable increase. Another reasonfor the difference between the data collected from the Intensity~2 graph and the dataobtained from the cards maybe due to the error that may have occurred in calculating themaximum intensity. As this intensity was calculated by projecting it beyond the boundariesof the paper an error may have occurred in calculating this value and this value may have

been in turn been transferred to the other intensities as the other intensities are calculatedrelative to the maximum intensity. Another error that may have occurred is in selecting the

average curve from which the height of a peak is calculated. Applying a high pressurewithout using a binder to cause cohesion while inserting the powder into the recess in theglass plate can also result in the particle taking certain orientations. This can also lead tohigh intensities for certain d values (this error can be avoided by using a binder to causecohesion between the powder and the glass face.

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