Magnetic dipole problem

1. Nov 23, 2004

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I need to find the field of a magnetic dipole embedded in the center of a linear magnetic sphere of radius R. My idea was that the field would be identical to that of a superposition of a dipole in a linear magnetic material throughout space and a surface current on the sphere equal to the bound surface current from this field. The answer I get for the field insid the sphere has the reduced dipole moment term right, and I also got that the extra term would be constant, and a multiple of the dipole moment. But where as I got this for the extra term:

$$-\frac{\mu}{4\pi}\frac{2(\mu_0 - \mu) \vec m}{(3\mu) R^3}$$

the book gave:

$$-\frac{\mu}{4\pi}\frac{2(\mu_0 - \mu) \vec m}{(2\mu_0 + \mu) R^3}$$

Do you know what I did wrong? I'm close, and I can't find a step where a simple change will result in this small difference in the final answer. Am I way off, and its just a coincidence its so close?

EDIT: Never mind, I got it.

Last edited: Nov 23, 2004