A contribution to the linear low temperature specific heat of dilute alloys arising from superparamagnetic clusters

Low temperature specific heat measurements on a copper +0.7 at% cobalt alloy isothermally aged at 400 degrees C indicate the existence of a linear magnetic cluster specific heat contribution as predicted by the theory of superparamagnetism. Quantitative analysis of the contribution making use of particle size data from magnetic measurements gives a mean anisotropy energy of order 10 6 erg cm -3 .