Cv as a function of temperature for ionic solid and metal

[helpcometk]

Homework Statement

The specific heat capacity per unit volume is denoted CV.Sketch Cv/T as a function of temperature T,in the limit T goes to zero, for both an ionic solid ,and a metal.Why do curves differ ?

Homework Equations

The question is very specific ,and in these cases as you know google is not very powerful.
I have searched carefully in the book of Kittel but no comprehesive answer is possible to be obtained from there .At least a hint here would be appreciated.

The Attempt at a Solution

 

[Crosshash]

Would it be okay to bump this question? I have a similar question and I can't find these plots anywhere.

 

[Mapes]

Try http://books.google.com/books?id=Zq...at capacity" temperature ionic metal&f=false" (from searching for "heat capacity" temperature ionic metal). Google Books is sometimes more useful than straight Google for this type of question.