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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: joe0515 on November 22, 2007, 12:52:29 PM

Title: Crystal structure
Post by: joe0515 on November 22, 2007, 12:52:29 PM
1.Calculate the theoretical volume change accompanying a polymorphic tranformation in a pure metal from FCC to BCC crystal structure. Assume the hard-sphere atomic model and that there is no change in atomic volume before and after the transformation ???

3.Randomization of atomic packing in amorphous metals genarally causes no more than a 1% drop in density compared with the crystalline structure of the same composition. Calculate the APF of an amorphous, thin film of nickel whose density is 8.84g/cm^3.The normal density of nickel in crystalline state is 8.91g/cm^3

4.A common way to describe the bonding energy E curve for secondary bonding is the 6-12 potential which state that E=-ka/a^6+kr/a^12,where ka and krare constants for attraction and repulsion, respectively. This relative simple form is a quantum mechanical result for this relatively simple blood type. Calculate the bond energy and bond length for argon(ka=10.37x10^-78Jm^6 and kr=16.16x10^-135Jm612)
Title: Re: Crystal structure
Post by: AWK on November 22, 2007, 01:01:21 PM
Show your attempts

search internet
Title: Re: Crystal structure
Post by: joe0515 on November 22, 2007, 01:02:15 PM
I already search whole day,cannot find anything :-[
Title: Re: Crystal structure
Post by: AWK on November 23, 2007, 05:32:35 AM
for 1
http://en.wikipedia.org/wiki/Atomic_packing_factor
For 2
http://en.wikipedia.org/wiki/Atomic_packing_factor
for 3
http://en.wikipedia.org/wiki/Lennard-Jones_potential