Size effects in critical phenomena in iron whiskers

Abstract
The Curie temperatures of whiskers of various sizes are compared by measuring the temperature dependence of the magnetic fields at which each whisker shows saturation in its midsection with two or three samples in the same detector coil. Whiskers of thicknesses of 50 μm or less show a decrease in Curie temperatures compared to thicker whiskers. The a.c. response near Tc of the thinner samples have exhibited long time dependent effects which might be associated with impurities and strain.