A method for the analysis of temperature and field dependent magnetization data near the Curie temperature is devised, which allows the reliable determination of critical exponents even in strongly inhomogeneous ferromagnets. It is shown, both experimentally and theoretically, that the field-induced broadening of the ferromagnetic phase transition follows a power law with a characteristic critical exponent β⋅δ, where β and δ are the conventional temperature and field dependent critical exponents of the magnetization. Experimental results on inhomogeneous films yield critical exponents and even though the intrinsic distribution width is larger than the field-induced effect.
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2002
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