A Simple Model to Describe Different Types of Exchange Bias Training Effect

Abstract

The exchange bias (EB) training effect, referring to the exchange field (H<inf>E</inf>) and/or the coercivity (H<inf>C</inf>) decreasing with the magnetic cycle (n), is often accompanied with EB. Usually, the EB training effect has different types, showing that H<inf>C1</inf> (coercive field at the descending branch) and H<inf>C2</inf> (coercive field at the ascending branch) change with n differently. In order to understand the origin producing the training type, a phenomenological model is therefore proposed. According to this model, how H<inf>C1</inf> (or H<inf>C2</inf>) changes with n is determined by the change of pinning magnetization at the descending (or ascending) branch during the training process. For verifying the validity of our model, various experimental training results with respect to different exchange-biased systems are selected for fitting and all the fitting results are nearly perfect.