The reversal mechanism and coercivity of Pt3Co alloy film

In this article, Pt₃Co alloy film is produced using a sputtering system. To understand the reversal mechanism of the Pt₃ Co alloy film, the recoil loops from the major hysteresis loop have been measured. The reversible magnetization M_rev dependence of the irreversible magnetization M_irr exhibits a minimum when M_irr is slightly larger than zero, which is the characteristic of a material that contains domain walls bowing during reversal caused by localized pinning due to dipolar fields for the films. By analyzing the linear dependence of the coercivity on the anisotropy field at different temperatures, the strength of the local dipolar fields N_eff, which influences the creation of the reversed magnetic nucleus, is estimated. We found a positive value of N _eff, which indicates that reversal process is favored by dipolar fields. It is also supposed that the dipolar fields originated from irregular local random anisotropy caused by residual stress, cavities, or inclusions, may be effective sources of pinning in the reversal process, and may strongly affect the coercivity of the film