Optimization of the ΔE effect in thin films and multilayers by magnetic field annealing

The ΔE effect of amorphous (Fe 90 Co 10 ) 78 Si 12 B 10 and Tb 40 Fe 60 thin films as well as of Tb 40 Fe 60 /Fe 50 Co 50 multilayers deposited on Si substrates using magnetron sputtering has been investigated. Influences of sputtering parameters and especially annealing conditions on the ΔE effect are discussed. In a field-annealed amorphous (Fe 90 Co 10 ) 78 Si 12 B 10 thin film, the AE effect is about 30%, assuming the Young's modulus of the film as 150 GPa. It was found that in case of thin-film substrate compounds, the magnetostrictive susceptibility is the determining factor of the size and field dependence of the ΔE effect.