Atomic Force Microscopy is the easiest technical for analysis any compound surface morphology.For Zno it is also possible to distinguish grain dimension surface morphology and substantially the porosity of the surface. If your AFM is equipped with EDX you can obtain the chemical composition of your sample and the proportion of all elements in your sample.Furthermore the spectra given by EDX gives the line positions of the emitted spectra and can determine which crystallographic plane is used when growing your sample.

Dr A.Ouerdane

@ A. Ouerdane. Thank you sir for the answer. Yes from the AFm data i can obtain the RMS value directly. But i would like to know the calculation of heigh- height correlation function through mathematical calculation.

The formula for correlation is as follows,

Correlation(r)=(N∑XY-∑X∑Y )/Racine[(N∑square X- square(∑square X))-the same for Y

Where,

X and Y are the variables.

b = the slope of the regression line is also called as the regression coefficient

a = intercept point of the regression line which is in the y-axis.

N = Number of values or elements

X = First Score

Y = Second Score

∑XY = Sum of the product of the first and Second Scores

∑X = Sum of First Scores

∑Y = Sum of Second Scores

∑X2 = Sum of square first scores.

∑Y2 = Sum of square second scores.

for more information consult the site :http://math.tutorvista.com/statistics/correlation.html

Please read where: little x and little y are the variables