Measurements of isothermal magnetization, initial and high-field static susceptibility, and magnetoresistance have been performed at various temperatures on five Ag100-xFex granular films of variable Fe content (10 <= x <= 30) obtained by cosputtering. Magnetoresistance and magnetization data have been systematically combined to determine the magnetic correlation volume in each sample and its evolution with temperature and magnetic field. A coherent picture of the whole set of Ag100-xFex films has been obtained. On increasing x, these alloys exhibit a magnetic behavior of increasing complexity, from the interacting superparamagnetic phase with weakly interacting magnetic moments and small correlation volumes to frustrated ferromagnetism with strong magnetic interactions, loss of physical identity of Fe particles, and extended correlation volumes. The degree of alignment of individual magnetic moments within a correlation volume and the stability of correlation volumes themselves against an external magnetic field are discussed in some detail.
Magnetic correlation states in cosputtered granular Ag100-xFex films
SPIZZO, Federico;
2006
Abstract
Measurements of isothermal magnetization, initial and high-field static susceptibility, and magnetoresistance have been performed at various temperatures on five Ag100-xFex granular films of variable Fe content (10 <= x <= 30) obtained by cosputtering. Magnetoresistance and magnetization data have been systematically combined to determine the magnetic correlation volume in each sample and its evolution with temperature and magnetic field. A coherent picture of the whole set of Ag100-xFex films has been obtained. On increasing x, these alloys exhibit a magnetic behavior of increasing complexity, from the interacting superparamagnetic phase with weakly interacting magnetic moments and small correlation volumes to frustrated ferromagnetism with strong magnetic interactions, loss of physical identity of Fe particles, and extended correlation volumes. The degree of alignment of individual magnetic moments within a correlation volume and the stability of correlation volumes themselves against an external magnetic field are discussed in some detail.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
