Dramatic depression of Curie temperature for magnetic Co/Cu(1 0 0) ultrathin films upon deposition at elevated temperature

The correlation between the crystalline structures and magnetic properties, such as magnetization and Curie temperature (TC) were investigated systematically by varying the deposition temperature of 2 ML fcc cobalt films on Cu(1 0 0) substrate. At variation of the deposition temperature a dramatic change in Curie temperature and coercivity of the films was observed. The drastic raising of Curie temperature were found for the films with the deposition temperatures from 340 K (TC=170 K) down to 275 K (TC=325 K). A simple theoretical estimation was proposed to evaluate the Curie temperature of the films in terms of magnetic moment as well as anisotropy with quantitative success. The enhanced Curie temperature can be attributed to the increase of the magnetic moments due to the alteration of film morphology with various deposition temperatures.