When we know the thickness of thin films, we can calculate the magnetization of films in emu/cc. Is there any way we could convert the magnetization from emu/cc to emu/gm?
Density is a relation. However why do you need it to convert it to emu/g? The volume magnetization is a true magnetization of the material. Mass magnetization (emu/g) is in use when a sample is not homogenous, it consists of different phases, inclusions, pores (like powdered samples), includes substrates and sample holders. When you are sure that measured magnetic moment relates only to a homogenous film of well-known volume, you can use emu/cc. If you aren't sure, then values of volume and density are indefinite and you cannot use them both. Then there is only way to compare your results with similar samples: to divide magnetic moment by sample weight and to apply emu/g.
Magnetization expressed in emu/cc is actually magnetization expressed per volume, while magnetization expressed is emu/grm is magnetization expressed per mass. These are old cgs units. In order to get the magnetization value in emu/grm, you would have to divide the value in emu/cc with material density of the film. Please note that you have to express the density in cgs units, which means in values of gcm-3.
To make things a little more clear at the bottom of the following link you will find some additional information on unit conversion.
I hope this helps out with your problem.
http://magician.ucsd.edu/essentials/webbookse7.html
Density is a relation. However why do you need it to convert it to emu/g? The volume magnetization is a true magnetization of the material. Mass magnetization (emu/g) is in use when a sample is not homogenous, it consists of different phases, inclusions, pores (like powdered samples), includes substrates and sample holders. When you are sure that measured magnetic moment relates only to a homogenous film of well-known volume, you can use emu/cc. If you aren't sure, then values of volume and density are indefinite and you cannot use them both. Then there is only way to compare your results with similar samples: to divide magnetic moment by sample weight and to apply emu/g.
Thank you all for the valuable suggestions. Actually I want to report my Magnetization data in terms of bohr magneton . I was using the following formula:
M = n X B X No X d/A
Where; M = magnetization in emu/gm or emu/cc
No= Number of atom/mole (6.02 x 10^23)
A= Atomic weight
n= number of unpaired electron spins/atom
B = value of a Bohr magneton
d = Density
I don't know the density of my material. So I calculated it the following way: considering one formula per unit cell I converted the molecular mass of it into gm and divided it by the unit cell volume. The I substituted this density in above formula along with magnetization in emu/cc. The values of Magnetization which I am getting in terms of bohr magneton are not matching with those in literature. My density calculation maybe wrong, before that I wanted to convert the magnetization in emu/gm and check what kind of values I get.
The reduced formula for bohr magneton B =( M x molecular weight)/5585 requires only M in emu/gm. That is the reason I want to convert M from emu/cc to emu/gm.
Magnetisation (B.M.) = (emu * mol. wt)/(sample wt. * 5585). This will give you a value in B.M./f.u.
sir I am doing this calculation for thin film and cannot measure its weight. So to use this formula I must convert emu/cc to emu/gm
Weigh the substrate before and after the film deposition to get the mass.
Simply divide the emu/cc by the mass density (density = gram/cc) you will get emu/g
Do not write emu/gm it should be written as emu/g only.
(emu/cc)/((g/cc) = emu/g simple. Enjoy.
vasudha the formula that I have mentioned above should help you do this once u convert the emu/cc to emu/g. you must know number of formula per unit cell that will give you an idea of how many Mn ions are present in one unit cell.
If you deal with a complex composite material which consists of magnetic and nonmagnetic phases, the exact value of mass of the ferromagnetic inclusions you can obtain by atomic absorption spectroscopy. At that tou destroy your sample. But the precision of mass determination is very high. In such a way you may convert emu/cc to emu/g.
You can calculate theoretical density of your material from XRD data, i.e from unit cell volume. I believe you did that. By the what is your materials? Why did you assume one formula unit per unit cell? If your material is spinel type, then you should consider 8 molecular formula unit per unit cell. It is same for pseudo-cubic perovskite structure.
How much deviated value have you obtained? Even your density calculation is correct, there are other reasons of such deviation.
Your formula is OK, where M must be volume magnetization (emu/cc) not mass magnetization (emu/g) . The difference beteween your result and literature may come from other things, such as temperature, magnetic signals from the substrate. It is not so difficult to solve them. On the other hand, imperfection of the film is more important for the difference, especially oxygen dificiency in manganite films. I think the error value within ~10% is acceptable.
Hi Fozia,
As in your formula, M = n X B X No X d/A
If we put values of all the parameters, this avogadro no. gives 10^23, which gives very strange values of magnetization.
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