Effect of Thickness on Magnetic Dipolar and Exchange Interactions in SmCo/FeCo/SmCo Thin Films

SmCo/FeCo/SmCo trilayer was deposited with two different thickness configurations for soft phase (FeCo); 50 nm/10 nm/50 nm and 50 nm/25 nm/50 nm were deposited on Si (111) sub-strate and Ta (50 nm) seed layer by RF magnetron sputtering in a pressure, p, of 30- 35 m Torr. After deposition the films were annealed under Ar atmosphere at temperature T equal to 923 and 973 for different times followed by quenching in water. X-ray diffraction patterns were obtained to identified phase presents and calculate average crystallite size. To study the effect of configura-tion thickness in soft phases, DC magnetic measurements were carried out; the measurements were done in the temperature interval of 300- 50 K. Hysteresis loops collected at low tempera-tures exposed an increment in coercivity with the decrease of T and at same time, presented a “knee ” in the second quadrant of the demagnetization curve, which suggests that the inter-layer exchange coupling becomes less effective, being more evident for sample with 50 nm/25 nm/5