Preparation and characterization of electrodeposited Co-Pt binary alloy film

Abstract

Co-Pt alloy films were electrodeposited from a novel bath which was designed in the present study containing the ammonia solution and ammonium tartrate as complexing agents. The Co-Pt deposited films were prepared with wide alloy compositions ranging from 16.5 at% Pt to 56.8 at% Pt by changing the bath concentration and current density. The structures of these deposited films were analyzed by means of XRD and HRTEM. The results indicated that the crystallographic structure of Co-Pt deposited film are the ε-Co solid solution when the platinum content in deposited film is below 31.1 at%, the mixture of ε-Co solid solution and (α-Co, Pt) face centered-cubic solid solution when the platinum in the deposited film is ranging from 35.7 at% to 45.7 at%, and the (α-Co, Pt) face centered-cubic solid solution when the platinum in the deposited film is ranging from 51.1 at% to 56.8 at%. Moreover, the ordered fct phase (L10) was detected with the help of XRD from Co-Pt deposited film with 51.1 at% Pt which was annealed in vacuum with pressure no lower 10-5 Pa for 60 min at the temperature of 450°C.