From your experimental termic dependecce of magnetic hardness χ-1 we can observe that the measured sample have a paramagnetic behaviour described by a Curie-Weis law:

χ=C/T-Tp where:

where:

Tp=232 (K)

Working in the nice cgs units of your figure, to apply Phlipp's formula, you need to convert your chi from susceptibility per gm to susceptibility per cm^3. And in your units mu_0=1. 

From your experimental termic dependecce of magnetic hardness χ-1 we can observe that the measured sample have a paramagnetic behaviour described by a Curie-Weis law:

χ=C/T-Tp where:

where:

Tp=232 (K)

Dear Professor Ioan Cosma,

I would like to convey my sincere thanks to you for your timely help.  I  am really very much grateful to you.

Thank you very much Professor.

Sincerely,

B. Sathya

I think my submissions are useful for you.

Knowledge of magnetic behavior of a material is made by measuring the mass-susceptibility versus temperature. But magnetic phases are better shown by the graph of the so called magnetic hardness (1/χ). So the linear part of your graph, show that the bulk behavior is paramagnetic; evidently, one of the free spin moments in the temperature range 120 ~ 290 K. The contributions to magnetic susceptibility of other ferro, or antiferro interactions, overlapping spin moments, are highlights below Tp, in the temperature range Tp -Tc (~ 10 - 20K, and diamagnetic smaller ones observable only at high temperatures. Their detecting and separating is very difficult and involves dynamic methods for determining. The issues raised by other respondents are correct, but in practice the-masse-susceptibility is measured; not volume or molar susceptibilities which are determined for each samples composition started from the first.

I have a related 'problem' in one of our student laborations.

We don't measure the susceptibility vs temperature but instead we measure the susceptibility in a VSM for a pill used as an iron source meant for blood donors. The pill pack says there is 60mg of Fe2+ in each pill.

Then we use this - material independant - formula for a Collection of non-interacting paramagnetic ions. We know the mass of the Fe and can easily calculate the cooresponding number of ions.

The objective is to determine the number of Bohr magnetons/ion. It is not difficult to get a number 5.5-5.7 (whereas I Think the literature value is 5.5....)

In any case it is a rewarding exercise for the students!

In statistical theory of paramagnetism, Langevin states that the thermal variation of susceptibility is : (See file)

Thank you professor

The value of effective moment is coming 0.13 ub , when we plug the C value in the formula suggested by Prof. Loan. I am bit confused. Could anyone please explain me. Whether it is typo mistake or something else..