Title :
Temperature variation of magnetic aftereffect
Author :
Torre, Edward Della ; Bennett, Lawrence H.
Author_Institution :
Nat. Inst. of Stand. & Technol., Gaithersburg, MD, USA
fDate :
5/1/2001 12:00:00 AM
Abstract :
The paper analyzes the anomalous behavior of the magnetic aftereffect decay coefficient with temperature, which has been established experimentally from a thermodynamic point of view. The Arrhenius law, which has often been used to model magnetic aftereffect, is based on the Maxwell-Boltzmann (MB) statistics. At low temperatures, however, magnons obey Bose-Einstein (BE) statistics, which have a different energy spectrum. MB statistics are a good approximation to BE statistics in the temperature range in which most devices operate. The variation in temperature, governed by chemical potential that is essentially linear, has a negative slope and is zero below a low but finite temperature. Other explanations for this anomalous behavior would predict an incorrect type of temperature dependence. This new interpretation of magnetic aftereffect may have profound implications on accelerated testing to determine life expectancy of recordings
Keywords :
chemical potential; life testing; magnetic aftereffect; magnetic recording; magnons; quantum statistical mechanics; Arrhenius law; Bose-Einstein statistics; Maxwell-Boltzmann statistics; accelerated testing; anomalous behavior; chemical potential; life expectancy; magnetic aftereffect; magnetic aftereffect decay coefficient; magnons; recording; temperature dependence; temperature variation; Chemicals; Iron; Life estimation; Magnetic analysis; Magnetic recording; Predictive models; Saturation magnetization; Statistics; Temperature dependence; Temperature distribution;
Journal_Title :
Magnetics, IEEE Transactions on