A while back I posted this:
>
>	We know that to obtain accurate X-ray diffraction intensities 
>
>       from a powder sample require that the grain size be small,
>
>	at least 10 microns and preferably small.
>
>	The question is how to obtain these particle-sizes and
>
>	how to sieve powders so small.
>	
>	I would be very gratefully if someone could answer me
	I had many interesting answers to this difficult problem. 
	
	Thanks a lot to all that spent some of your
	time in answering my question.
        Now, we are working with a Retsch Spectro Mill. It seems
	to be capable of producing sizes about 5 microns easily.
 
			Best wishes.
			Miguel A. Salvado
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        Miguel A. Salvado
        Dpto. Quimica Fisica y Analitica
        Universidad de Oviedo
	E-mail: mass@dwarf1.quimica.uniovi.es
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