CoPt Nanowires with tunable composition: Magnetic and Structural Characterization

MANUEL VÁZQUEZ; FERNANDO MENESES; PAULA G. BERCOFF; CRISTINA BRAN

Richmond

Otro; IEEE Magnetics Society Summer School; 2019

Virginia Commonwealth University - IEEE Magnetic Society

Arrays of cylindrical alloyed nanowires with noble (Pt) and magnetic (Co) metals were synthesized in highly ordered alumina templates with pores of 60 nm diameter. The electrodeposition technique allowed controlling the composition of the samples, from Co 90 at% to 70 at%. The magnetic properties of the arrays were studied by measuring the angular dependence of coercivity, while the microstructure was determined by X-ray diffraction, and the morphology by scanning electron microscopy. The samples were characterized prior and after annealing in Argon atmosphere (1 atm) at 550 °C. Different behaviors were observed depending on the Co/Pt ratio in the alloy. Particularly, it is possible to control the coercivity and the magnetization reversal mechanisms by selecting the proper composition. Furthermore, annealing the samples improves its magnetic hardening, and a notorious jump in coercivity is observed in the Co 70 at% annealed sample. The results presented in this work give rise to new expectations for further control of the magnetic properties, especially the magnetic hardening, by tuning the noble/magnetic composition ratio.